Small data transmission

ABSTRACT

A wireless device, in a radio resource control (RRC) idle state or RRC inactive state, transmits, to a base station, a message. The message comprises first data associated with a small data transmission (SDT) procedure and an RRC request message. While the wireless device is in the RRC idle state or RRC inactive state, the wireless device receives, from the base station, an indication of an uplink resource, transmits, via the uplink resource, second data associated with the SDT procedure, and receives, from the base station and after the transmitting the second data, an RRC release message.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/US2021/032002, filed May 12, 2021, which claims the benefit of U.S.Provisional Application No. 63/024,827, filed May 14, 2020, all of whichare hereby incorporated by reference in their entireties.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of several of the various embodiments of the present disclosureare described herein with reference to the drawings.

FIG. 1A and FIG. 1B illustrate example mobile communication networks inwhich embodiments of the present disclosure may be implemented.

FIG. 2A and FIG. 2B respectively illustrate a New Radio (NR) user planeand control plane protocol stack.

FIG. 3 illustrates an example of services provided between protocollayers of the NR user plane protocol stack of FIG. 2A.

FIG. 4A illustrates an example downlink data flow through the NR userplane protocol stack of FIG. 2A.

FIG. 4B illustrates an example format of a MAC subheader in a MAC PDU.

FIG. 5A and FIG. 5B respectively illustrate a mapping between logicalchannels, transport channels, and physical channels for the downlink anduplink.

FIG. 6 is an example diagram showing RRC state transitions of a UE.

FIG. 7 illustrates an example configuration of an NR frame into whichOFDM symbols are grouped.

FIG. 8 illustrates an example configuration of a slot in the time andfrequency domain for an NR carrier.

FIG. 9 illustrates an example of bandwidth adaptation using threeconfigured BWPs for an NR carrier.

FIG. 10A illustrates three carrier aggregation configurations with twocomponent carriers.

FIG. 10B illustrates an example of how aggregated cells may beconfigured into one or more PUCCH groups.

FIG. 11A illustrates an example of an SS/PBCH block structure andlocation.

FIG. 11B illustrates an example of CSI-RSs that are mapped in the timeand frequency domains.

FIG. 12A and FIG. 12B respectively illustrate examples of three downlinkand uplink beam management procedures.

FIG. 13A, FIG. 13B, and FIG. 13C respectively illustrate a four-stepcontention-based random access procedure, a two-step contention-freerandom access procedure, and another two-step random access procedure.

FIG. 14A illustrates an example of CORESET configurations for abandwidth part.

FIG. 14B illustrates an example of a CCE-to-REG mapping for DCItransmission on a CORESET and PDCCH processing.

FIG. 15 illustrates an example of a wireless device in communicationwith a base station.

FIG. 16A, FIG. 16B, FIG. 16C, and FIG. 16D illustrate example structuresfor uplink and downlink transmission.

FIG. 17 illustrates an example of an RRC connection reestablishmentprocedure.

FIG. 18 illustrates an example of an RRC connection resume procedure.

FIG. 19 illustrates an example of UE actions for RRC release message.

FIG. 20 illustrates an example of UP small data transmission.

FIG. 21 illustrates an example of CP small data transmission.

FIG. 22 illustrates an example of consecutive UP small datatransmissions.

FIG. 23 illustrates an example diagram of UP EDT and CP EDT.

FIG. 24 illustrates an example of UP EDT.

FIG. 25 illustrates an example of UP PUR and CP PUR.

FIG. 26 illustrates an example of UP PUR.

FIG. 27 illustrates an example of consecutive UP small datatransmissions.

FIG. 28 illustrates an example of subsequent transmission after UP smalldata transmission.

FIG. 29 illustrates an example of (first) response message comprisingRRC release message in subsequent transmission.

FIG. 30 illustrates an example diagram of embodiments in accordance withthe disclosure.

FIG. 31 illustrates an example diagram of embodiments in accordance withthe disclosure.

FIG. 32 illustrates an example diagram of consecutive UP small datatransmissions based on subsequent transmission with receiving RRCrelease message comprising suspend configuration parameters.

FIG. 33 illustrates an example of consecutive UP small datatransmissions based on subsequent transmission with receiving RRCrelease message comprising suspend configuration parameters.

FIG. 34 illustrates an example of subsequent transmission based onsubsequent configuration parameters.

FIG. 35 illustrates an example of subsequent transmission withconsecutive UP small data transmissions.

FIG. 36 illustrates an example of RRC timer for subsequent transmission.

DETAILED DESCRIPTION

In the present disclosure, various embodiments are presented as examplesof how the disclosed techniques may be implemented and/or how thedisclosed techniques may be practiced in environments and scenarios. Itwill be apparent to persons skilled in the relevant art that variouschanges in form and detail can be made therein without departing fromthe scope. In fact, after reading the description, it will be apparentto one skilled in the relevant art how to implement alternativeembodiments. The present embodiments should not be limited by any of thedescribed exemplary embodiments. The embodiments of the presentdisclosure will be described with reference to the accompanyingdrawings. Limitations, features, and/or elements from the disclosedexample embodiments may be combined to create further embodiments withinthe scope of the disclosure. Any figures which highlight thefunctionality and advantages, are presented for example purposes only.The disclosed architecture is sufficiently flexible and configurable,such that it may be utilized in ways other than that shown. For example,the actions listed in any flowchart may be re-ordered or only optionallyused in some embodiments.

Embodiments may be configured to operate as needed. The disclosedmechanism may be performed when certain criteria are met, for example,in a wireless device, a base station, a radio environment, a network, acombination of the above, and/or the like. Example criteria may bebased, at least in part, on for example, wireless device or network nodeconfigurations, traffic load, initial system set up, packet sizes,traffic characteristics, a combination of the above, and/or the like.When the one or more criteria are met, various example embodiments maybe applied. Therefore, it may be possible to implement exampleembodiments that selectively implement disclosed protocols.

A base station may communicate with a mix of wireless devices. Wirelessdevices and/or base stations may support multiple technologies, and/ormultiple releases of the same technology. Wireless devices may have somespecific capability(ies) depending on wireless device category and/orcapability(ies). When this disclosure refers to a base stationcommunicating with a plurality of wireless devices, this disclosure mayrefer to a subset of the total wireless devices in a coverage area. Thisdisclosure may refer to, for example, a plurality of wireless devices ofa given LTE or 5G release with a given capability and in a given sectorof the base station. The plurality of wireless devices in thisdisclosure may refer to a selected plurality of wireless devices, and/ora subset of total wireless devices in a coverage area which performaccording to disclosed methods, and/or the like. There may be aplurality of base stations or a plurality of wireless devices in acoverage area that may not comply with the disclosed methods, forexample, those wireless devices or base stations may perform based onolder releases of LTE or 5G technology.

In this disclosure, “a” and “an” and similar phrases are to beinterpreted as “at least one” and “one or more.” Similarly, any termthat ends with the suffix “(s)” is to be interpreted as “at least one”and “one or more.” In this disclosure, the term “may” is to beinterpreted as “may, for example.” In other words, the term “may” isindicative that the phrase following the term “may” is an example of oneof a multitude of suitable possibilities that may, or may not, beemployed by one or more of the various embodiments. The terms“comprises” and “consists of”, as used herein, enumerate one or morecomponents of the element being described. The term “comprises” isinterchangeable with “includes” and does not exclude unenumeratedcomponents from being included in the element being described. Bycontrast, “consists of” provides a complete enumeration of the one ormore components of the element being described. The term “based on”, asused herein, should be interpreted as “based at least in part on” ratherthan, for example, “based solely on”. The term “and/or” as used hereinrepresents any possible combination of enumerated elements. For example,“A, B, and/or C” may represent A; B; C; A and B; A and C; B and C; or A,B, and C.

If A and B are sets and every element of A is an element of B, A iscalled a subset of B. In this specification, only non-empty sets andsubsets are considered. For example, possible subsets of B={cell1,cell2} are: {cell1}, {cell2}, and {cell1, cell2}. The phrase “based on”(or equally “based at least on”) is indicative that the phrase followingthe term “based on” is an example of one of a multitude of suitablepossibilities that may, or may not, be employed to one or more of thevarious embodiments. The phrase “in response to” (or equally “inresponse at least to”) is indicative that the phrase following thephrase “in response to” is an example of one of a multitude of suitablepossibilities that may, or may not, be employed to one or more of thevarious embodiments. The phrase “depending on” (or equally “depending atleast to”) is indicative that the phrase following the phrase “dependingon” is an example of one of a multitude of suitable possibilities thatmay, or may not, be employed to one or more of the various embodiments.The phrase “employing/using” (or equally “employing/using at least”) isindicative that the phrase following the phrase “employing/using” is anexample of one of a multitude of suitable possibilities that may, or maynot, be employed to one or more of the various embodiments.

The term configured may relate to the capacity of a device whether thedevice is in an operational or non-operational state. Configured mayrefer to specific settings in a device that effect the operationalcharacteristics of the device whether the device is in an operational ornon-operational state. In other words, the hardware, software, firmware,registers, memory values, and/or the like may be “configured” within adevice, whether the device is in an operational or nonoperational state,to provide the device with specific characteristics. Terms such as “acontrol message to cause in a device” may mean that a control messagehas parameters that may be used to configure specific characteristics ormay be used to implement certain actions in the device, whether thedevice is in an operational or non-operational state.

In this disclosure, parameters (or equally called, fields, orInformation elements: IEs) may comprise one or more information objects,and an information object may comprise one or more other objects. Forexample, if parameter (IE) N comprises parameter (IE) M, and parameter(IE) M comprises parameter (IE) K, and parameter (IE) K comprisesparameter (information element) J. Then, for example, N comprises K, andN comprises J. In an example embodiment, when one or more messagescomprise a plurality of parameters, it implies that a parameter in theplurality of parameters is in at least one of the one or more messages,but does not have to be in each of the one or more messages.

Many features presented are described as being optional through the useof “may” or the use of parentheses. For the sake of brevity andlegibility, the present disclosure does not explicitly recite each andevery permutation that may be obtained by choosing from the set ofoptional features. The present disclosure is to be interpreted asexplicitly disclosing all such permutations. For example, a systemdescribed as having three optional features may be embodied in sevenways, namely with just one of the three possible features, with any twoof the three possible features or with three of the three possiblefeatures.

Many of the elements described in the disclosed embodiments may beimplemented as modules. A module is defined here as an element thatperforms a defined function and has a defined interface to otherelements. The modules described in this disclosure may be implemented inhardware, software in combination with hardware, firmware, wetware (e.g.hardware with a biological element) or a combination thereof, which maybe behaviorally equivalent. For example, modules may be implemented as asoftware routine written in a computer language configured to beexecuted by a hardware machine (such as C, C++, Fortran, Java, Basic,Matlab or the like) or a modeling/simulation program such as Simulink,Stateflow, GNU Octave, or Lab VIEWMathScript. It may be possible toimplement modules using physical hardware that incorporates discrete orprogrammable analog, digital and/or quantum hardware. Examples ofprogrammable hardware comprise: computers, microcontrollers,microprocessors, application-specific integrated circuits (ASICs); fieldprogrammable gate arrays (FPGAs); and complex programmable logic devices(CPLDs). Computers, microcontrollers and microprocessors are programmedusing languages such as assembly, C, C++ or the like. FPGAs, ASICs andCPLDs are often programmed using hardware description languages (HDL)such as VHSIC hardware description language (VHDL) or Verilog thatconfigure connections between internal hardware modules with lesserfunctionality on a programmable device. The mentioned technologies areoften used in combination to achieve the result of a functional module.

FIG. 1A illustrates an example of a mobile communication network 100 inwhich embodiments of the present disclosure may be implemented. Themobile communication network 100 may be, for example, a public landmobile network (PLMN) run by a network operator. As illustrated in FIG.1A, the mobile communication network 100 includes a core network (CN)102, a radio access network (RAN) 104, and a wireless device 106.

The CN 102 may provide the wireless device 106 with an interface to oneor more data networks (DNs), such as public DNs (e.g., the Internet),private DNs, and/or intra-operator DNs. As part of the interfacefunctionality, the CN 102 may set up end-to-end connections between thewireless device 106 and the one or more DNs, authenticate the wirelessdevice 106, and provide charging functionality.

The RAN 104 may connect the CN 102 to the wireless device 106 throughradio communications over an air interface. As part of the radiocommunications, the RAN 104 may provide scheduling, radio resourcemanagement, and retransmission protocols. The communication directionfrom the RAN 104 to the wireless device 106 over the air interface isknown as the downlink and the communication direction from the wirelessdevice 106 to the RAN 104 over the air interface is known as the uplink.Downlink transmissions may be separated from uplink transmissions usingfrequency division duplexing (FDD), time-division duplexing (TDD),and/or some combination of the two duplexing techniques.

The term wireless device may be used throughout this disclosure to referto and encompass any mobile device or fixed (non-mobile) device forwhich wireless communication is needed or usable. For example, awireless device may be a telephone, smart phone, tablet, computer,laptop, sensor, meter, wearable device, Internet of Things (IoT) device,vehicle road side unit (RSU), relay node, automobile, and/or anycombination thereof. The term wireless device encompasses otherterminology, including user equipment (UE), user terminal (UT), accessterminal (AT), mobile station, handset, wireless transmit and receiveunit (WTRU), and/or wireless communication device.

The RAN 104 may include one or more base stations (not shown). The termbase station may be used throughout this disclosure to refer to andencompass a Node B (associated with UMTS and/or 3G standards), anEvolved Node B (eNB, associated with E-UTRA and/or 4G standards), aremote radio head (RRH), a baseband processing unit coupled to one ormore RRHs, a repeater node or relay node used to extend the coveragearea of a donor node, a Next Generation Evolved Node B (ng-eNB), aGeneration Node B (gNB, associated with NR and/or 5G standards), anaccess point (AP, associated with, for example, WiFi or any othersuitable wireless communication standard), and/or any combinationthereof. A base station may comprise at least one gNB Central Unit(gNB-CU) and at least one a gNB Distributed Unit (gNB-DU).

A base station included in the RAN 104 may include one or more sets ofantennas for communicating with the wireless device 106 over the airinterface. For example, one or more of the base stations may includethree sets of antennas to respectively control three cells (or sectors).The size of a cell may be determined by a range at which a receiver(e.g., a base station receiver) can successfully receive thetransmissions from a transmitter (e.g., a wireless device transmitter)operating in the cell. Together, the cells of the base stations mayprovide radio coverage to the wireless device 106 over a wide geographicarea to support wireless device mobility.

In addition to three-sector sites, other implementations of basestations are possible. For example, one or more of the base stations inthe RAN 104 may be implemented as a sectored site with more or less thanthree sectors. One or more of the base stations in the RAN 104 may beimplemented as an access point, as a baseband processing unit coupled toseveral remote radio heads (RRHs), and/or as a repeater or relay nodeused to extend the coverage area of a donor node. A baseband processingunit coupled to RRHs may be part of a centralized or cloud RANarchitecture, where the baseband processing unit may be eithercentralized in a pool of baseband processing units or virtualized. Arepeater node may amplify and rebroadcast a radio signal received from adonor node. A relay node may perform the same/similar functions as arepeater node but may decode the radio signal received from the donornode to remove noise before amplifying and rebroadcasting the radiosignal.

The RAN 104 may be deployed as a homogenous network of macrocell basestations that have similar antenna patterns and similar high-leveltransmit powers. The RAN 104 may be deployed as a heterogeneous network.In heterogeneous networks, small cell base stations may be used toprovide small coverage areas, for example, coverage areas that overlapwith the comparatively larger coverage areas provided by macrocell basestations. The small coverage areas may be provided in areas with highdata traffic (or so-called “hotspots”) or in areas with weak macrocellcoverage. Examples of small cell base stations include, in order ofdecreasing coverage area, microcell base stations, picocell basestations, and femtocell base stations or home base stations.

The Third-Generation Partnership Project (3GPP) was formed in 1998 toprovide global standardization of specifications for mobilecommunication networks similar to the mobile communication network 100in FIG. 1A. To date, 3GPP has produced specifications for threegenerations of mobile networks: a third generation (3G) network known asUniversal Mobile Telecommunications System (UMTS), a fourth generation(4G) network known as Long-Term Evolution (LTE), and a fifth generation(5G) network known as 5G System (5GS). Embodiments of the presentdisclosure are described with reference to the RAN of a 3GPP 5G network,referred to as next-generation RAN (NG-RAN). Embodiments may beapplicable to RANs of other mobile communication networks, such as theRAN 104 in FIG. 1A, the RANs of earlier 3G and 4G networks, and those offuture networks yet to be specified (e.g., a 3GPP 6G network). NG-RANimplements 5G radio access technology known as New Radio (NR) and may beprovisioned to implement 4G radio access technology or other radioaccess technologies, including non-3GPP radio access technologies.

FIG. 1B illustrates another example mobile communication network 150 inwhich embodiments of the present disclosure may be implemented. Mobilecommunication network 150 may be, for example, a PLMN run by a networkoperator. As illustrated in FIG. 1B, mobile communication network 150includes a 5G core network (5G-CN) 152, an NG-RAN 154, and UEs 156A and156B (collectively UEs 156). These components may be implemented andoperate in the same or similar manner as corresponding componentsdescribed with respect to FIG. 1A.

The 5G-CN 152 provides the UEs 156 with an interface to one or more DNs,such as public DNs (e.g., the Internet), private DNs, and/orintra-operator DNs. As part of the interface functionality, the 5G-CN152 may set up end-to-end connections between the UEs 156 and the one ormore DNs, authenticate the UEs 156, and provide charging functionality.Compared to the CN of a 3GPP 4G network, the basis of the 5G-CN 152 maybe a service-based architecture. This means that the architecture of thenodes making up the 5G-CN 152 may be defined as network functions thatoffer services via interfaces to other network functions. The networkfunctions of the 5G-CN 152 may be implemented in several ways, includingas network elements on dedicated or shared hardware, as softwareinstances running on dedicated or shared hardware, or as virtualizedfunctions instantiated on a platform (e.g., a cloud-based platform).

As illustrated in FIG. 1B, the 5G-CN 152 includes an Access and MobilityManagement Function (AMF) 158A and a User Plane Function (UPF) 158B,which are shown as one component AMF/UPF 158 in FIG. 1B for ease ofillustration. The UPF 158B may serve as a gateway between the NG-RAN 154and the one or more DNs. The UPF 158B may perform functions such aspacket routing and forwarding, packet inspection and user plane policyrule enforcement, traffic usage reporting, uplink classification tosupport routing of traffic flows to the one or more DNs, quality ofservice (QoS) handling for the user plane (e.g., packet filtering,gating, uplink/downlink rate enforcement, and uplink trafficverification), downlink packet buffering, and downlink data notificationtriggering. The UPF 158B may serve as an anchor point forintra-/inter-Radio Access Technology (RAT) mobility, an externalprotocol (or packet) data unit (PDU) session point of interconnect tothe one or more DNs, and/or a branching point to support a multi-homedPDU session. The UEs 156 may be configured to receive services through aPDU session, which is a logical connection between a UE and a DN.

The AMF 158A may perform functions such as Non-Access Stratum (NAS)signaling termination, NAS signaling security, Access Stratum (AS)security control, inter-CN node signaling for mobility between 3GPPaccess networks, idle mode UE reachability (e.g., control and executionof paging retransmission), registration area management, intra-systemand inter-system mobility support, access authentication, accessauthorization including checking of roaming rights, mobility managementcontrol (subscription and policies), network slicing support, and/orsession management function (SMF) selection. NAS may refer to thefunctionality operating between a CN and a UE, and AS may refer to thefunctionality operating between the UE and a RAN.

The 5G-CN 152 may include one or more additional network functions thatare not shown in FIG. 1B for the sake of clarity. For example, the 5G-CN152 may include one or more of a Session Management Function (SMF), anNR Repository Function (NRF), a Policy Control Function (PCF), a NetworkExposure Function (NEF), a Unified Data Management (UDM), an ApplicationFunction (AF), and/or an Authentication Server Function (AUSF).

The NG-RAN 154 may connect the 5G-CN 152 to the UEs 156 through radiocommunications over the air interface. The NG-RAN 154 may include one ormore gNB s, illustrated as gNB 160A and gNB 160B (collectively gNBs 160)and/or one or more ng-eNB s, illustrated as ng-eNB 162A and ng-eNB 162B(collectively ng-eNB s 162). The gNBs 160 and ng-eNBs 162 may be moregenerically referred to as base stations. The gNBs 160 and ng-eNB s 162may include one or more sets of antennas for communicating with the UEs156 over an air interface. For example, one or more of the gNBs 160and/or one or more of the ng-eNBs 162 may include three sets of antennasto respectively control three cells (or sectors). Together, the cells ofthe gNBs 160 and the ng-eNBs 162 may provide radio coverage to the UEs156 over a wide geographic area to support UE mobility.

As shown in FIG. 1B, the gNBs 160 and/or the ng-eNB s 162 may beconnected to the 5G-CN 152 by means of an NG interface and to other basestations by an Xn interface. The NG and Xn interfaces may be establishedusing direct physical connections and/or indirect connections over anunderlying transport network, such as an internet protocol (IP)transport network. The gNB s 160 and/or the ng-eNB s 162 may beconnected to the UEs 156 by means of a Uu interface. For example, asillustrated in FIG. 1B, gNB 160A may be connected to the UE 156A bymeans of a Uu interface. The NG, Xn, and Uu interfaces are associatedwith a protocol stack. The protocol stacks associated with theinterfaces may be used by the network elements in FIG. 1B to exchangedata and signaling messages and may include two planes: a user plane anda control plane. The user plane may handle data of interest to a user.The control plane may handle signaling messages of interest to thenetwork elements.

The gNBs 160 and/or the ng-eNB s 162 may be connected to one or moreAMF/UPF functions of the 5G-CN 152, such as the AMF/UPF 158, by means ofone or more NG interfaces. For example, the gNB 160A may be connected tothe UPF 158B of the AMF/UPF 158 by means of an NG-User plane (NG-U)interface. The NG-U interface may provide delivery (e.g., non-guaranteeddelivery) of user plane PDUs between the gNB 160A and the UPF 158B. ThegNB 160A may be connected to the AMF 158A by means of an NG-Controlplane (NG-C) interface. The NG-C interface may provide, for example, NGinterface management, UE context management, UE mobility management,transport of NAS messages, paging, PDU session management, andconfiguration transfer and/or warning message transmission.

The gNBs 160 may provide NR user plane and control plane protocolterminations towards the UEs 156 over the Uu interface. For example, thegNB 160A may provide NR user plane and control plane protocolterminations toward the UE 156A over a Uu interface associated with afirst protocol stack. The ng-eNBs 162 may provide Evolved UMTSTerrestrial Radio Access (E-UTRA) user plane and control plane protocolterminations towards the UEs 156 over a Uu interface, where E-UTRArefers to the 3GPP 4G radio-access technology. For example, the ng-eNB162B may provide E-UTRA user plane and control plane protocolterminations towards the UE 156B over a Uu interface associated with asecond protocol stack.

The 5G-CN 152 was described as being configured to handle NR and 4Gradio accesses. It will be appreciated by one of ordinary skill in theart that it may be possible for NR to connect to a 4G core network in amode known as “non-standalone operation.” In non-standalone operation, a4G core network is used to provide (or at least support) control-planefunctionality (e.g., initial access, mobility, and paging). Althoughonly one AMF/UPF 158 is shown in FIG. 1B, one gNB or ng-eNB may beconnected to multiple AMF/UPF nodes to provide redundancy and/or to loadshare across the multiple AMF/UPF nodes.

As discussed, an interface (e.g., Uu, Xn, and NG interfaces) between thenetwork elements in FIG. 1B may be associated with a protocol stack thatthe network elements use to exchange data and signaling messages. Aprotocol stack may include two planes: a user plane and a control plane.The user plane may handle data of interest to a user, and the controlplane may handle signaling messages of interest to the network elements.

FIG. 2A and FIG. 2B respectively illustrate examples of NR user planeand NR control plane protocol stacks for the Uu interface that liesbetween a UE 210 and a gNB 220. The protocol stacks illustrated in FIG.2A and FIG. 2B may be the same or similar to those used for the Uuinterface between, for example, the UE 156A and the gNB 160A shown inFIG. 1B.

FIG. 2A illustrates a NR user plane protocol stack comprising fivelayers implemented in the UE 210 and the gNB 220. At the bottom of theprotocol stack, physical layers (PHYs) 211 and 221 may provide transportservices to the higher layers of the protocol stack and may correspondto layer 1 of the Open Systems Interconnection (OSI) model. The nextfour protocols above PHYs 211 and 221 comprise media access controllayers (MACs) 212 and 222, radio link control layers (RLCs) 213 and 223,packet data convergence protocol layers (PDCPs) 214 and 224, and servicedata application protocol layers (SDAPs) 215 and 225. Together, thesefour protocols may make up layer 2, or the data link layer, of the OSImodel.

FIG. 3 illustrates an example of services provided between protocollayers of the NR user plane protocol stack. Starting from the top ofFIG. 2A and FIG. 3 , the SDAPs 215 and 225 may perform QoS flowhandling. The UE 210 may receive services through a PDU session, whichmay be a logical connection between the UE 210 and a DN. The PDU sessionmay have one or more QoS flows. A UPF of a CN (e.g., the UPF 158B) maymap IP packets to the one or more QoS flows of the PDU session based onQoS requirements (e.g., in terms of delay, data rate, and/or errorrate). The SDAPs 215 and 225 may perform mapping/de-mapping between theone or more QoS flows and one or more data radio bearers. Themapping/de-mapping between the QoS flows and the data radio bearers maybe determined by the SDAP 225 at the gNB 220. The SDAP 215 at the UE 210may be informed of the mapping between the QoS flows and the data radiobearers through reflective mapping or control signaling received fromthe gNB 220. For reflective mapping, the SDAP 225 at the gNB 220 maymark the downlink packets with a QoS flow indicator (QFI), which may beobserved by the SDAP 215 at the UE 210 to determine themapping/de-mapping between the QoS flows and the data radio bearers.

The PDCPs 214 and 224 may perform header compression/decompression toreduce the amount of data that needs to be transmitted over the airinterface, ciphering/deciphering to prevent unauthorized decoding ofdata transmitted over the air interface, and integrity protection (toensure control messages originate from intended sources. The PDCPs 214and 224 may perform retransmissions of undelivered packets, in-sequencedelivery and reordering of packets, and removal of packets received induplicate due to, for example, an intra-gNB handover. The PDCPs 214 and224 may perform packet duplication to improve the likelihood of thepacket being received and, at the receiver, remove any duplicatepackets. Packet duplication may be useful for services that require highreliability.

Although not shown in FIG. 3 , PDCPs 214 and 224 may performmapping/de-mapping between a split radio bearer and RLC channels in adual connectivity scenario. Dual connectivity is a technique that allowsa UE to connect to two cells or, more generally, two cell groups: amaster cell group (MCG) and a secondary cell group (SCG). A split beareris when a single radio bearer, such as one of the radio bearers providedby the PDCPs 214 and 224 as a service to the SDAPs 215 and 225, ishandled by cell groups in dual connectivity. The PDCPs 214 and 224 maymap/de-map the split radio bearer between RLC channels belonging to cellgroups.

The RLCs 213 and 223 may perform segmentation, retransmission throughAutomatic Repeat Request (ARQ), and removal of duplicate data unitsreceived from MACs 212 and 222, respectively. The RLCs 213 and 223 maysupport three transmission modes: transparent mode (TM); unacknowledgedmode (UM); and acknowledged mode (AM). Based on the transmission mode anRLC is operating, the RLC may perform one or more of the notedfunctions. The RLC configuration may be per logical channel with nodependency on numerologies and/or Transmission Time Interval (TTI)durations. As shown in FIG. 3 , the RLCs 213 and 223 may provide RLCchannels as a service to PDCPs 214 and 224, respectively.

The MACs 212 and 222 may perform multiplexing/demultiplexing of logicalchannels and/or mapping between logical channels and transport channels.The multiplexing/demultiplexing may include multiplexing/demultiplexingof data units, belonging to the one or more logical channels, into/fromTransport Blocks (TBs) delivered to/from the PHYs 211 and 221. The MAC222 may be configured to perform scheduling, scheduling informationreporting, and priority handling between UEs by means of dynamicscheduling. Scheduling may be performed in the gNB 220 (at the MAC 222)for downlink and uplink. The MACs 212 and 222 may be configured toperform error correction through Hybrid Automatic Repeat Request (HARQ)(e.g., one HARQ entity per carrier in case of Carrier Aggregation (CA)),priority handling between logical channels of the UE 210 by means oflogical channel prioritization, and/or padding. The MACs 212 and 222 maysupport one or more numerologies and/or transmission timings. In anexample, mapping restrictions in a logical channel prioritization maycontrol which numerology and/or transmission timing a logical channelmay use. As shown in FIG. 3 , the MACs 212 and 222 may provide logicalchannels as a service to the RLCs 213 and 223.

The PHYs 211 and 221 may perform mapping of transport channels tophysical channels and digital and analog signal processing functions forsending and receiving information over the air interface. These digitaland analog signal processing functions may include, for example,coding/decoding and modulation/demodulation. The PHYs 211 and 221 mayperform multi-antenna mapping. As shown in FIG. 3 , the PHYs 211 and 221may provide one or more transport channels as a service to the MACs 212and 222.

FIG. 4A illustrates an example downlink data flow through the NR userplane protocol stack. FIG. 4A illustrates a downlink data flow of threeIP packets (n, n+1, and m) through the NR user plane protocol stack togenerate two TBs at the gNB 220. An uplink data flow through the NR userplane protocol stack may be similar to the downlink data flow depictedin FIG. 4A.

The downlink data flow of FIG. 4A begins when SDAP 225 receives thethree IP packets from one or more QoS flows and maps the three packetsto radio bearers. In FIG. 4A, the SDAP 225 maps IP packets n and n+1 toa first radio bearer 402 and maps IP packet m to a second radio bearer404. An SDAP header (labeled with an “H” in FIG. 4A) is added to an IPpacket. The data unit from/to a higher protocol layer is referred to asa service data unit (SDU) of the lower protocol layer and the data unitto/from a lower protocol layer is referred to as a protocol data unit(PDU) of the higher protocol layer. As shown in FIG. 4A, the data unitfrom the SDAP 225 is an SDU of lower protocol layer PDCP 224 and is aPDU of the SDAP 225.

The remaining protocol layers in FIG. 4A may perform their associatedfunctionality (e.g., with respect to FIG. 3 ), add correspondingheaders, and forward their respective outputs to the next lower layer.For example, the PDCP 224 may perform IP-header compression andciphering and forward its output to the RLC 223. The RLC 223 mayoptionally perform segmentation (e.g., as shown for IP packet m in FIG.4A) and forward its output to the MAC 222. The MAC 222 may multiplex anumber of RLC PDUs and may attach a MAC subheader to an RLC PDU to forma transport block. In NR, the MAC subheaders may be distributed acrossthe MAC PDU, as illustrated in FIG. 4A. In LTE, the MAC subheaders maybe entirely located at the beginning of the MAC PDU. The NR MAC PDUstructure may reduce processing time and associated latency because theMAC PDU subheaders may be computed before the full MAC PDU is assembled.

FIG. 4B illustrates an example format of a MAC subheader in a MAC PDU.The MAC subheader includes: an SDU length field for indicating thelength (e.g., in bytes) of the MAC SDU to which the MAC subheadercorresponds; a logical channel identifier (LCID) field for identifyingthe logical channel from which the MAC SDU originated to aid in thedemultiplexing process; a flag (F) for indicating the size of the SDUlength field; and a reserved bit (R) field for future use.

FIG. 4B further illustrates MAC control elements (CEs) inserted into theMAC PDU by a MAC, such as MAC 223 or MAC 222. For example, FIG. 4Billustrates two MAC CEs inserted into the MAC PDU. MAC CEs may beinserted at the beginning of a MAC PDU for downlink transmissions (asshown in FIG. 4B) and at the end of a MAC PDU for uplink transmissions.MAC CEs may be used for in-band control signaling. Example MAC CEsinclude: scheduling-related MAC CEs, such as buffer status reports andpower headroom reports; activation/deactivation MAC CEs, such as thosefor activation/deactivation of PDCP duplication detection, channel stateinformation (CSI) reporting, sounding reference signal (SRS)transmission, and prior configured components; discontinuous reception(DRX) related MAC CEs; timing advance MAC CEs; and random access relatedMAC CEs. A MAC CE may be preceded by a MAC subheader with a similarformat as described for MAC SDUs and may be identified with a reservedvalue in the LCID field that indicates the type of control informationincluded in the MAC CE.

Before describing the NR control plane protocol stack, logical channels,transport channels, and physical channels are first described as well asa mapping between the channel types. One or more of the channels may beused to carry out functions associated with the NR control planeprotocol stack described later below.

FIG. 5A and FIG. 5B illustrate, for downlink and uplink respectively, amapping between logical channels, transport channels, and physicalchannels. Information is passed through channels between the RLC, theMAC, and the PHY of the NR protocol stack. A logical channel may be usedbetween the RLC and the MAC and may be classified as a control channelthat carries control and configuration information in the NR controlplane or as a traffic channel that carries data in the NR user plane. Alogical channel may be classified as a dedicated logical channel that isdedicated to a specific UE or as a common logical channel that may beused by more than one UE. A logical channel may also be defined by thetype of information it carries. The set of logical channels defined byNR include, for example:

-   -   a paging control channel (PCCH) for carrying paging messages        used to page a UE whose location is not known to the network on        a cell level;    -   a broadcast control channel (BCCH) for carrying system        information messages in the form of a master information block        (MIB) and several system information blocks (SIBs), wherein the        system information messages may be used by the UEs to obtain        information about how a cell is configured and how to operate        within the cell;    -   a common control channel (CCCH) for carrying control messages        together with random access;    -   a dedicated control channel (DCCH) for carrying control messages        to/from a specific the UE to configure the UE; and    -   a dedicated traffic channel (DTCH) for carrying user data        to/from a specific the UE.

Transport channels are used between the MAC and PHY layers and may bedefined by how the information they carry is transmitted over the airinterface. The set of transport channels defined by NR include, forexample:

-   -   a paging channel (PCH) for carrying paging messages that        originated from the PCCH;    -   a broadcast channel (BCH) for carrying the MIB from the BCCH;    -   a downlink shared channel (DL-SCH) for carrying downlink data        and signaling messages, including the SIBs from the BCCH;    -   an uplink shared channel (UL-SCH) for carrying uplink data and        signaling messages; and    -   a random access channel (RACH) for allowing a UE to contact the        network without any prior scheduling.

The PHY may use physical channels to pass information between processinglevels of the PHY. A physical channel may have an associated set oftime-frequency resources for carrying the information of one or moretransport channels. The PHY may generate control information to supportthe low-level operation of the PHY and provide the control informationto the lower levels of the PHY via physical control channels, known asL1/L2 control channels. The set of physical channels and physicalcontrol channels defined by NR include, for example:

-   -   a physical broadcast channel (PBCH) for carrying the MIB from        the BCH;    -   a physical downlink shared channel (PDSCH) for carrying downlink        data and signaling messages from the DL-SCH, as well as paging        messages from the PCH;    -   a physical downlink control channel (PDCCH) for carrying        downlink control information (DCI), which may include downlink        scheduling commands, uplink scheduling grants, and uplink power        control commands;    -   a physical uplink shared channel (PUSCH) for carrying uplink        data and signaling messages from the UL-SCH and in some        instances uplink control information (UCI) as described below;    -   a physical uplink control channel (PUCCH) for carrying UCI,        which may include HARQ acknowledgments, channel quality        indicators (CQI), pre-coding matrix indicators (PMI), rank        indicators (RI), and scheduling requests (SR); and    -   a physical random access channel (PRACH) for random access.

Similar to the physical control channels, the physical layer generatesphysical signals to support the low-level operation of the physicallayer. As shown in FIG. 5A and FIG. 5B, the physical layer signalsdefined by NR include: primary synchronization signals (PSS), secondarysynchronization signals (SSS), channel state information referencesignals (CSI-RS), demodulation reference signals (DMRS), soundingreference signals (SRS), and phase-tracking reference signals (PT-RS).These physical layer signals will be described in greater detail below.

FIG. 2B illustrates an example NR control plane protocol stack. As shownin FIG. 2B, the NR control plane protocol stack may use the same/similarfirst four protocol layers as the example NR user plane protocol stack.These four protocol layers include the PHYs 211 and 221, the MACs 212and 222, the RLCs 213 and 223, and the PDCPs 214 and 224. Instead ofhaving the SDAPs 215 and 225 at the top of the stack as in the NR userplane protocol stack, the NR control plane stack has radio resourcecontrols (RRCs) 216 and 226 and NAS protocols 217 and 237 at the top ofthe NR control plane protocol stack.

The NAS protocols 217 and 237 may provide control plane functionalitybetween the UE 210 and the AMF 230 (e.g., the AMF 158A) or, moregenerally, between the UE 210 and the CN. The NAS protocols 217 and 237may provide control plane functionality between the UE 210 and the AMF230 via signaling messages, referred to as NAS messages. There is nodirect path between the UE 210 and the AMF 230 through which the NASmessages can be transported. The NAS messages may be transported usingthe AS of the Uu and NG interfaces. NAS protocols 217 and 237 mayprovide control plane functionality such as authentication, security,connection setup, mobility management, and session management.

The RRCs 216 and 226 may provide control plane functionality between theUE 210 and the gNB 220 or, more generally, between the UE 210 and theRAN. The RRCs 216 and 226 may provide control plane functionalitybetween the UE 210 and the gNB 220 via signaling messages, referred toas RRC messages. RRC messages may be transmitted between the UE 210 andthe RAN using signaling radio bearers and the same/similar PDCP, RLC,MAC, and PHY protocol layers. The MAC may multiplex control-plane anduser-plane data into the same transport block (TB). The RRCs 216 and 226may provide control plane functionality such as: broadcast of systeminformation related to AS and NAS; paging initiated by the CN or theRAN; establishment, maintenance and release of an RRC connection betweenthe UE 210 and the RAN; security functions including key management;establishment, configuration, maintenance and release of signaling radiobearers and data radio bearers; mobility functions; QoS managementfunctions; the UE measurement reporting and control of the reporting;detection of and recovery from radio link failure (RLF); and/or NASmessage transfer. As part of establishing an RRC connection, RRCs 216and 226 may establish an RRC context, which may involve configuringparameters for communication between the UE 210 and the RAN.

FIG. 6 is an example diagram showing RRC state transitions of a UE. TheUE may be the same or similar to the wireless device 106 depicted inFIG. 1A, the UE 210 depicted in FIG. 2A and FIG. 2B, or any otherwireless device described in the present disclosure. As illustrated inFIG. 6 , a UE may be in at least one of three RRC states: RRC connected602 (e.g., RRC CONNECTED), RRC idle 604 (e.g., RRC_IDLE), and RRCinactive 606 (e.g., RRC_INACTIVE).

In RRC connected 602, the UE has an established RRC context and may haveat least one RRC connection with a base station. The base station may besimilar to one of the one or more base stations included in the RAN 104depicted in FIG. 1A, one of the gNB s 160 or ng-eNB s 162 depicted inFIG. 1B, the gNB 220 depicted in FIG. 2A and FIG. 2B, or any other basestation described in the present disclosure. The base station with whichthe UE is connected may have the RRC context for the UE. The RRCcontext, referred to as the UE context, may comprise parameters forcommunication between the UE and the base station. These parameters mayinclude, for example: one or more AS contexts; one or more radio linkconfiguration parameters; bearer configuration information (e.g.,relating to a data radio bearer, signaling radio bearer, logicalchannel, QoS flow, and/or PDU session); security information; and/orPHY, MAC, RLC, PDCP, and/or SDAP layer configuration information. Whilein RRC connected 602, mobility of the UE may be managed by the RAN(e.g., the RAN 104 or the NG-RAN 154). The UE may measure the signallevels (e.g., reference signal levels) from a serving cell andneighboring cells and report these measurements to the base stationcurrently serving the UE. The UE's serving base station may request ahandover to a cell of one of the neighboring base stations based on thereported measurements. The RRC state may transition from RRC connected602 to RRC idle 604 through a connection release procedure 608 or to RRCinactive 606 through a connection inactivation procedure 610.

In RRC idle 604, an RRC context may not be established for the UE. InRRC idle 604, the UE may not have an RRC connection with the basestation. While in RRC idle 604, the UE may be in a sleep state for themajority of the time (e.g., to conserve battery power). The UE may wakeup periodically (e.g., once in every discontinuous reception cycle) tomonitor for paging messages from the RAN. Mobility of the UE may bemanaged by the UE through a procedure known as cell reselection. The RRCstate may transition from RRC idle 604 to RRC connected 602 through aconnection establishment procedure 612, which may involve a randomaccess procedure as discussed in greater detail below.

In RRC inactive 606, the RRC context previously established ismaintained in the UE and the base station. This allows for a fasttransition to RRC connected 602 with reduced signaling overhead ascompared to the transition from RRC idle 604 to RRC connected 602. Whilein RRC inactive 606, the UE may be in a sleep state and mobility of theUE may be managed by the UE through cell reselection. The RRC state maytransition from RRC inactive 606 to RRC connected 602 through aconnection resume procedure 614 or to RRC idle 604 though a connectionrelease procedure 616 that may be the same as or similar to connectionrelease procedure 608.

An RRC state may be associated with a mobility management mechanism. InRRC idle 604 and RRC inactive 606, mobility is managed by the UE throughcell reselection. The purpose of mobility management in RRC idle 604 andRRC inactive 606 is to allow the network to be able to notify the UE ofan event via a paging message without having to broadcast the pagingmessage over the entire mobile communications network. The mobilitymanagement mechanism used in RRC idle 604 and RRC inactive 606 may allowthe network to track the UE on a cell-group level so that the pagingmessage may be broadcast over the cells of the cell group that the UEcurrently resides within instead of the entire mobile communicationnetwork. The mobility management mechanisms for RRC idle 604 and RRCinactive 606 track the UE on a cell-group level. They may do so usingdifferent granularities of grouping. For example, there may be threelevels of cell-grouping granularity: individual cells; cells within aRAN area identified by a RAN area identifier (RAI); and cells within agroup of RAN areas, referred to as a tracking area and identified by atracking area identifier (TAI).

Tracking areas may be used to track the UE at the CN level. The CN(e.g., the CN 102 or the 5G-CN 152) may provide the UE with a list ofTAIs associated with a UE registration area. If the UE moves, throughcell reselection, to a cell associated with a TAI not included in thelist of TAIs associated with the UE registration area, the UE mayperform a registration update with the CN to allow the CN to update theUE's location and provide the UE with a new the UE registration area.

RAN areas may be used to track the UE at the RAN level. For a UE in RRCinactive 606 state, the UE may be assigned a RAN notification area. ARAN notification area may comprise one or more cell identities, a listof RAIs, or a list of TAIs. In an example, a base station may belong toone or more RAN notification areas. In an example, a cell may belong toone or more RAN notification areas. If the UE moves, through cellreselection, to a cell not included in the RAN notification areaassigned to the UE, the UE may perform a notification area update withthe RAN to update the UE's RAN notification area.

A base station storing an RRC context for a UE or a last serving basestation of the UE may be referred to as an anchor base station. Ananchor base station may maintain an RRC context for the UE at leastduring a period of time that the UE stays in a RAN notification area ofthe anchor base station and/or during a period of time that the UE staysin RRC inactive 606.

A gNB, such as gNBs 160 in FIG. 1B, may be split in two parts: a centralunit (gNB-CU), and one or more distributed units (gNB-DU). A gNB-CU maybe coupled to one or more gNB-DUs using an F1 interface. The gNB-CU maycomprise the RRC, the PDCP, and the SDAP. A gNB-DU may comprise the RLC,the MAC, and the PHY.

In NR, the physical signals and physical channels (discussed withrespect to FIG. 5A and FIG. 5B) may be mapped onto orthogonal frequencydivisional multiplexing (OFDM) symbols. OFDM is a multicarriercommunication scheme that transmits data over F orthogonal subcarriers(or tones). Before transmission, the data may be mapped to a series ofcomplex symbols (e.g., M-quadrature amplitude modulation (M-QAM) orM-phase shift keying (M-PSK) symbols), referred to as source symbols,and divided into F parallel symbol streams. The F parallel symbolstreams may be treated as though they are in the frequency domain andused as inputs to an Inverse Fast Fourier Transform (IFFT) block thattransforms them into the time domain. The IFFT block may take in Fsource symbols at a time, one from each of the F parallel symbolstreams, and use each source symbol to modulate the amplitude and phaseof one of F sinusoidal basis functions that correspond to the Forthogonal subcarriers. The output of the IFFT block may be Ftime-domain samples that represent the summation of the F orthogonalsubcarriers. The F time-domain samples may form a single OFDM symbol.After some processing (e.g., addition of a cyclic prefix) andup-conversion, an OFDM symbol provided by the IFFT block may betransmitted over the air interface on a carrier frequency. The Fparallel symbol streams may be mixed using an FFT block before beingprocessed by the IFFT block. This operation produces Discrete FourierTransform (DFT)-precoded OFDM symbols and may be used by UEs in theuplink to reduce the peak to average power ratio (PAPR). Inverseprocessing may be performed on the OFDM symbol at a receiver using anFFT block to recover the data mapped to the source symbols.

FIG. 7 illustrates an example configuration of an NR frame into whichOFDM symbols are grouped. An NR frame may be identified by a systemframe number (SFN). The SFN may repeat with a period of 1024 frames. Asillustrated, one NR frame may be 10 milliseconds (ms) in duration andmay include 10 subframes that are 1 ms in duration. A subframe may bedivided into slots that include, for example, 14 OFDM symbols per slot.

The duration of a slot may depend on the numerology used for the OFDMsymbols of the slot. In NR, a flexible numerology is supported toaccommodate different cell deployments (e.g., cells with carrierfrequencies below 1 GHz up to cells with carrier frequencies in themm-wave range). A numerology may be defined in terms of subcarrierspacing and cyclic prefix duration. For a numerology in NR, subcarrierspacings may be scaled up by powers of two from a baseline subcarrierspacing of 15 kHz, and cyclic prefix durations may be scaled down bypowers of two from a baseline cyclic prefix duration of 4.7 μs. Forexample, NR defines numerologies with the following subcarrierspacing/cyclic prefix duration combinations: 15 kHz/4.7 μs; 30 kHz/2.3μs; 60 kHz/1.2 μs; 120 kHz/0.59 μs; and 240 kHz/0.29 μs.

A slot may have a fixed number of OFDM symbols (e.g., 14 OFDM symbols).A numerology with a higher subcarrier spacing has a shorter slotduration and, correspondingly, more slots per subframe. FIG. 7illustrates this numerology-dependent slot duration andslots-per-subframe transmission structure (the numerology with asubcarrier spacing of 240 kHz is not shown in FIG. 7 for ease ofillustration). A subframe in NR may be used as a numerology-independenttime reference, while a slot may be used as the unit upon which uplinkand downlink transmissions are scheduled. To support low latency,scheduling in NR may be decoupled from the slot duration and start atany OFDM symbol and last for as many symbols as needed for atransmission. These partial slot transmissions may be referred to asmini-slot or subslot transmissions.

FIG. 8 illustrates an example configuration of a slot in the time andfrequency domain for an NR carrier. The slot includes resource elements(REs) and resource blocks (RBs). An RE is the smallest physical resourcein NR. An RE spans one OFDM symbol in the time domain by one subcarrierin the frequency domain as shown in FIG. 8 . An RB spans twelveconsecutive REs in the frequency domain as shown in FIG. 8 . An NRcarrier may be limited to a width of 275 RBs or 275×12=3300 subcarriers.Such a limitation, if used, may limit the NR carrier to 50, 100, 200,and 400 MHz for subcarrier spacings of 15, 30, 60, and 120 kHz,respectively, where the 400 MHz bandwidth may be set based on a 400 MHzper carrier bandwidth limit.

FIG. 8 illustrates a single numerology being used across the entirebandwidth of the NR carrier. In other example configurations, multiplenumerologies may be supported on the same carrier.

NR may support wide carrier bandwidths (e.g., up to 400 MHz for asubcarrier spacing of 120 kHz). Not all UEs may be able to receive thefull carrier bandwidth (e.g., due to hardware limitations). Also,receiving the full carrier bandwidth may be prohibitive in terms of UEpower consumption. In an example, to reduce power consumption and/or forother purposes, a UE may adapt the size of the UE's receive bandwidthbased on the amount of traffic the UE is scheduled to receive. This isreferred to as bandwidth adaptation.

NR defines bandwidth parts (BWPs) to support UEs not capable ofreceiving the full carrier bandwidth and to support bandwidthadaptation. In an example, a BWP may be defined by a subset ofcontiguous RBs on a carrier. A UE may be configured (e.g., via an RRClayer) with one or more downlink BWPs and one or more uplink BWPs perserving cell (e.g., up to four downlink BWPs and up to four uplink BWPsper serving cell). At a given time, one or more of the configured BWPsfor a serving cell may be active. These one or more BWPs may be referredto as active BWPs of the serving cell. When a serving cell is configuredwith a secondary uplink carrier, the serving cell may have one or morefirst active BWPs in the uplink carrier and one or more second activeBWPs in the secondary uplink carrier.

For unpaired spectra, a downlink BWP from a set of configured downlinkBWPs may be linked with an uplink BWP from a set of configured uplinkBWPs if a downlink BWP index of the downlink BWP and an uplink BWP indexof the uplink BWP are the same. For unpaired spectra, a UE may expectthat a center frequency for a downlink BWP is the same as a centerfrequency for an uplink BWP.

For a downlink BWP in a set of configured downlink BWPs on a primarycell (PCell), a base station may configure a UE with one or more controlresource sets (CORESETs) for at least one search space. A search spaceis a set of locations in the time and frequency domains where the UE mayfind control information. The search space may be a UE-specific searchspace or a common search space (potentially usable by a plurality ofUEs). For example, a base station may configure a UE with a commonsearch space, on a PCell or on a primary secondary cell (PSCell), in anactive downlink BWP.

For an uplink BWP in a set of configured uplink BWPs, a BS may configurea UE with one or more resource sets for one or more PUCCH transmissions.A UE may receive downlink receptions (e.g., PDCCH or PDSCH) in adownlink BWP according to a configured numerology (e.g., subcarrierspacing and cyclic prefix duration) for the downlink BWP. The UE maytransmit uplink transmissions (e.g., PUCCH or PUSCH) in an uplink BWPaccording to a configured numerology (e.g., subcarrier spacing andcyclic prefix length for the uplink BWP).

One or more BWP indicator fields may be provided in Downlink ControlInformation (DCI). A value of a BWP indicator field may indicate whichBWP in a set of configured BWPs is an active downlink BWP for one ormore downlink receptions. The value of the one or more BWP indicatorfields may indicate an active uplink BWP for one or more uplinktransmissions.

A base station may semi-statically configure a UE with a defaultdownlink BWP within a set of configured downlink BWPs associated with aPCell. If the base station does not provide the default downlink BWP tothe UE, the default downlink BWP may be an initial active downlink BWP.The UE may determine which BWP is the initial active downlink BWP basedon a CORESET configuration obtained using the PBCH.

A base station may configure a UE with a BWP inactivity timer value fora PCell. The UE may start or restart a BWP inactivity timer at anyappropriate time. For example, the UE may start or restart the BWPinactivity timer (a) when the UE detects a DCI indicating an activedownlink BWP other than a default downlink BWP for a paired spectraoperation; or (b) when a UE detects a DCI indicating an active downlinkBWP or active uplink BWP other than a default downlink BWP or uplink BWPfor an unpaired spectra operation. If the UE does not detect DCI duringan interval of time (e.g., 1 ms or 0.5 ms), the UE may run the BWPinactivity timer toward expiration (for example, increment from zero tothe BWP inactivity timer value, or decrement from the BWP inactivitytimer value to zero). When the BWP inactivity timer expires, the UE mayswitch from the active downlink BWP to the default downlink BWP.

In an example, a base station may semi-statically configure a UE withone or more BWPs. A UE may switch an active BWP from a first BWP to asecond BWP in response to receiving a DCI indicating the second BWP asan active BWP and/or in response to an expiry of the BWP inactivitytimer (e.g., if the second BWP is the default BWP).

Downlink and uplink BWP switching (where BWP switching refers toswitching from a currently active BWP to a not currently active BWP) maybe performed independently in paired spectra. In unpaired spectra,downlink and uplink BWP switching may be performed simultaneously.Switching between configured BWPs may occur based on RRC signaling, DCI,expiration of a BWP inactivity timer, and/or an initiation of randomaccess.

FIG. 9 illustrates an example of bandwidth adaptation using threeconfigured BWPs for an NR carrier. A UE configured with the three BWPsmay switch from one BWP to another BWP at a switching point. In theexample illustrated in FIG. 9 , the BWPs include: a BWP 902 with abandwidth of 40 MHz and a subcarrier spacing of 15 kHz; a BWP 904 with abandwidth of 10 MHz and a subcarrier spacing of 15 kHz; and a BWP 906with a bandwidth of 20 MHz and a subcarrier spacing of 60 kHz. The BWP902 may be an initial active BWP, and the BWP 904 may be a default BWP.The UE may switch between BWPs at switching points. In the example ofFIG. 9 , the UE may switch from the BWP 902 to the BWP 904 at aswitching point 908. The switching at the switching point 908 may occurfor any suitable reason, for example, in response to an expiry of a BWPinactivity timer (indicating switching to the default BWP) and/or inresponse to receiving a DCI indicating BWP 904 as the active BWP. The UEmay switch at a switching point 910 from active BWP 904 to BWP 906 inresponse receiving a DCI indicating BWP 906 as the active BWP. The UEmay switch at a switching point 912 from active BWP 906 to BWP 904 inresponse to an expiry of a BWP inactivity timer and/or in responsereceiving a DCI indicating BWP 904 as the active BWP. The UE may switchat a switching point 914 from active BWP 904 to BWP 902 in responsereceiving a DCI indicating BWP 902 as the active BWP.

If a UE is configured for a secondary cell with a default downlink BWPin a set of configured downlink BWPs and a timer value, UE proceduresfor switching BWPs on a secondary cell may be the same/similar as thoseon a primary cell. For example, the UE may use the timer value and thedefault downlink BWP for the secondary cell in the same/similar manneras the UE would use these values for a primary cell.

To provide for greater data rates, two or more carriers can beaggregated and simultaneously transmitted to/from the same UE usingcarrier aggregation (CA). The aggregated carriers in CA may be referredto as component carriers (CCs). When CA is used, there are a number ofserving cells for the UE, one for a CC. The CCs may have threeconfigurations in the frequency domain.

FIG. 10A illustrates the three CA configurations with two CCs. In theintraband, contiguous configuration 1002, the two CCs are aggregated inthe same frequency band (frequency band A) and are located directlyadjacent to each other within the frequency band. In the intraband,non-contiguous configuration 1004, the two CCs are aggregated in thesame frequency band (frequency band A) and are separated in thefrequency band by a gap. In the interband configuration 1006, the twoCCs are located in frequency bands (frequency band A and frequency bandB).

In an example, up to 32 CCs may be aggregated. The aggregated CCs mayhave the same or different bandwidths, subcarrier spacing, and/orduplexing schemes (TDD or FDD). A serving cell for a UE using CA mayhave a downlink CC. For FDD, one or more uplink CCs may be optionallyconfigured for a serving cell. The ability to aggregate more downlinkcarriers than uplink carriers may be useful, for example, when the UEhas more data traffic in the downlink than in the uplink.

When CA is used, one of the aggregated cells for a UE may be referred toas a primary cell (PCell). The PCell may be the serving cell that the UEinitially connects to at RRC connection establishment, reestablishment,and/or handover. The PCell may provide the UE with NAS mobilityinformation and the security input. UEs may have different PCells. Inthe downlink, the carrier corresponding to the PCell may be referred toas the downlink primary CC (DL PCC). In the uplink, the carriercorresponding to the PCell may be referred to as the uplink primary CC(UL PCC). The other aggregated cells for the UE may be referred to assecondary cells (SCells). In an example, the SCells may be configuredafter the PCell is configured for the UE. For example, an SCell may beconfigured through an RRC Connection Reconfiguration procedure. In thedownlink, the carrier corresponding to an SCell may be referred to as adownlink secondary CC (DL SCC). In the uplink, the carrier correspondingto the SCell may be referred to as the uplink secondary CC (UL SCC).

Configured SCells for a UE may be activated and deactivated based on,for example, traffic and channel conditions. Deactivation of an SCellmay mean that PDCCH and PDSCH reception on the SCell is stopped andPUSCH, SRS, and CQI transmissions on the SCell are stopped. ConfiguredSCells may be activated and deactivated using a MAC CE with respect toFIG. 4B. For example, a MAC CE may use a bitmap (e.g., one bit perSCell) to indicate which SCells (e.g., in a subset of configured SCells)for the UE are activated or deactivated. Configured SCells may bedeactivated in response to an expiration of an SCell deactivation timer(e.g., one SCell deactivation timer per SCell).

Downlink control information, such as scheduling assignments andscheduling grants, for a cell may be transmitted on the cellcorresponding to the assignments and grants, which is known asself-scheduling. The DCI for the cell may be transmitted on anothercell, which is known as cross-carrier scheduling. Uplink controlinformation (e.g., HARQ acknowledgments and channel state feedback, suchas CQI, PMI, and/or RI) for aggregated cells may be transmitted on thePUCCH of the PCell. For a larger number of aggregated downlink CCs, thePUCCH of the PCell may become overloaded. Cells may be divided intomultiple PUCCH groups.

FIG. 10B illustrates an example of how aggregated cells may beconfigured into one or more PUCCH groups. A PUCCH group 1010 and a PUCCHgroup 1050 may include one or more downlink CCs, respectively. In theexample of FIG. 10B, the PUCCH group 1010 includes three downlink CCs: aPCell 1011, an SCell 1012, and an SCell 1013. The PUCCH group 1050includes three downlink CCs in the present example: a PCell 1051, anSCell 1052, and an SCell 1053. One or more uplink CCs may be configuredas a PCell 1021, an SCell 1022, and an SCell 1023. One or more otheruplink CCs may be configured as a primary SCell (PSCell) 1061, an SCell1062, and an SCell 1063. Uplink control information (UCI) related to thedownlink CCs of the PUCCH group 1010, shown as UCI 1031, UCI 1032, andUCI 1033, may be transmitted in the uplink of the PCell 1021. Uplinkcontrol information (UCI) related to the downlink CCs of the PUCCH group1050, shown as UCI 1071, UCI 1072, and UCI 1073, may be transmitted inthe uplink of the PSCell 1061. In an example, if the aggregated cellsdepicted in FIG. 10B were not divided into the PUCCH group 1010 and thePUCCH group 1050, a single uplink PCell to transmit UCI relating to thedownlink CCs, and the PCell may become overloaded. By dividingtransmissions of UCI between the PCell 1021 and the PSCell 1061,overloading may be prevented.

A cell, comprising a downlink carrier and optionally an uplink carrier,may be assigned with a physical cell ID and a cell index. The physicalcell ID or the cell index may identify a downlink carrier and/or anuplink carrier of the cell, for example, depending on the context inwhich the physical cell ID is used. A physical cell ID may be determinedusing a synchronization signal transmitted on a downlink componentcarrier. A cell index may be determined using RRC messages. In thedisclosure, a physical cell ID may be referred to as a carrier ID, and acell index may be referred to as a carrier index. For example, when thedisclosure refers to a first physical cell ID for a first downlinkcarrier, the disclosure may mean the first physical cell ID is for acell comprising the first downlink carrier. The same/similar concept mayapply to, for example, a carrier activation. When the disclosureindicates that a first carrier is activated, the specification may meanthat a cell comprising the first carrier is activated.

In CA, a multi-carrier nature of a PHY may be exposed to a MAC. In anexample, a HARQ entity may operate on a serving cell. A transport blockmay be generated per assignment/grant per serving cell. A transportblock and potential HARQ retransmissions of the transport block may bemapped to a serving cell.

In the downlink, a base station may transmit (e.g., unicast, multicast,and/or broadcast) one or more Reference Signals (RSs) to a UE (e.g.,PSS, SSS, CSI-RS, DMRS, and/or PT-RS, as shown in FIG. 5A). In theuplink, the UE may transmit one or more RSs to the base station (e.g.,DMRS, PT-RS, and/or SRS, as shown in FIG. 5B). The PSS and the SSS maybe transmitted by the base station and used by the UE to synchronize theUE to the base station. The PSS and the SSS may be provided in asynchronization signal (SS)/physical broadcast channel (PBCH) block thatincludes the PSS, the SSS, and the PBCH. The base station mayperiodically transmit a burst of SS/PBCH blocks.

FIG. 11A illustrates an example of an SS/PBCH block's structure andlocation. A burst of SS/PBCH blocks may include one or more SS/PBCHblocks (e.g., 4 SS/PBCH blocks, as shown in FIG. 11A). Bursts may betransmitted periodically (e.g., every 2 frames or 20 ms). A burst may berestricted to a half-frame (e.g., a first half-frame having a durationof 5 ms). It will be understood that FIG. 11A is an example, and thatthese parameters (number of SS/PBCH blocks per burst, periodicity ofbursts, position of burst within the frame) may be configured based on,for example: a carrier frequency of a cell in which the SS/PBCH block istransmitted; a numerology or subcarrier spacing of the cell; aconfiguration by the network (e.g., using RRC signaling); or any othersuitable factor. In an example, the UE may assume a subcarrier spacingfor the SS/PBCH block based on the carrier frequency being monitored,unless the radio network configured the UE to assume a differentsubcarrier spacing.

The SS/PBCH block may span one or more OFDM symbols in the time domain(e.g., 4 OFDM symbols, as shown in the example of FIG. 11A) and may spanone or more subcarriers in the frequency domain (e.g., 240 contiguoussubcarriers). The PSS, the SSS, and the PBCH may have a common centerfrequency. The PSS may be transmitted first and may span, for example, 1OFDM symbol and 127 subcarriers. The SSS may be transmitted after thePSS (e.g., two symbols later) and may span 1 OFDM symbol and 127subcarriers. The PBCH may be transmitted after the PSS (e.g., across thenext 3 OFDM symbols) and may span 240 subcarriers.

The location of the SS/PBCH block in the time and frequency domains maynot be known to the UE (e.g., if the UE is searching for the cell). Tofind and select the cell, the UE may monitor a carrier for the PSS. Forexample, the UE may monitor a frequency location within the carrier. Ifthe PSS is not found after a certain duration (e.g., 20 ms), the UE maysearch for the PSS at a different frequency location within the carrier,as indicated by a synchronization raster. If the PSS is found at alocation in the time and frequency domains, the UE may determine, basedon a known structure of the SS/PBCH block, the locations of the SSS andthe PBCH, respectively. The SS/PBCH block may be a cell-defining SSblock (CD-SSB). In an example, a primary cell may be associated with aCD-SSB. The CD-SSB may be located on a synchronization raster. In anexample, a cell selection/search and/or reselection may be based on theCD-SSB.

The SS/PBCH block may be used by the UE to determine one or moreparameters of the cell. For example, the UE may determine a physicalcell identifier (PCI) of the cell based on the sequences of the PSS andthe SSS, respectively. The UE may determine a location of a frameboundary of the cell based on the location of the SS/PBCH block. Forexample, the SS/PBCH block may indicate that it has been transmitted inaccordance with a transmission pattern, wherein a SS/PBCH block in thetransmission pattern is a known distance from the frame boundary.

The PBCH may use a QPSK modulation and may use forward error correction(FEC). The FEC may use polar coding. One or more symbols spanned by thePBCH may carry one or more DMRSs for demodulation of the PBCH. The PBCHmay include an indication of a current system frame number (SFN) of thecell and/or a SS/PBCH block timing index. These parameters mayfacilitate time synchronization of the UE to the base station. The PBCHmay include a master information block (MIB) used to provide the UE withone or more parameters. The MIB may be used by the UE to locateremaining minimum system information (RMSI) associated with the cell.The RMSI may include a System Information Block Type 1 (SIB1). The SIB1may contain information needed by the UE to access the cell. The UE mayuse one or more parameters of the MIB to monitor PDCCH, which may beused to schedule PDSCH. The PDSCH may include the SIB1. The SIB1 may bedecoded using parameters provided in the MIB. The PBCH may indicate anabsence of SIB1. Based on the PBCH indicating the absence of SIB1, theUE may be pointed to a frequency. The UE may search for an SS/PBCH blockat the frequency to which the UE is pointed.

The UE may assume that one or more SS/PBCH blocks transmitted with asame SS/PBCH block index are quasi co-located (QCLed) (e.g., having thesame/similar Doppler spread, Doppler shift, average gain, average delay,and/or spatial Rx parameters). The UE may not assume QCL for SS/PBCHblock transmissions having different SS/PBCH block indices.

SS/PBCH blocks (e.g., those within a half-frame) may be transmitted inspatial directions (e.g., using different beams that span a coveragearea of the cell). In an example, a first SS/PBCH block may betransmitted in a first spatial direction using a first beam, and asecond SS/PBCH block may be transmitted in a second spatial directionusing a second beam.

In an example, within a frequency span of a carrier, a base station maytransmit a plurality of SS/PBCH blocks. In an example, a first PCI of afirst SS/PBCH block of the plurality of SS/PBCH blocks may be differentfrom a second PCI of a second SS/PBCH block of the plurality of SS/PBCHblocks. The PCIs of SS/PBCH blocks transmitted in different frequencylocations may be different or the same.

The CSI-RS may be transmitted by the base station and used by the UE toacquire channel state information (CSI). The base station may configurethe UE with one or more CSI-RSs for channel estimation or any othersuitable purpose. The base station may configure a UE with one or moreof the same/similar CSI-RSs. The UE may measure the one or more CSI-RSs.The UE may estimate a downlink channel state and/or generate a CSIreport based on the measuring of the one or more downlink CSI-RSs. TheUE may provide the CSI report to the base station. The base station mayuse feedback provided by the UE (e.g., the estimated downlink channelstate) to perform link adaptation.

The base station may semi-statically configure the UE with one or moreCSI-RS resource sets. A CSI-RS resource may be associated with alocation in the time and frequency domains and a periodicity. The basestation may selectively activate and/or deactivate a CSI-RS resource.The base station may indicate to the UE that a CSI-RS resource in theCSI-RS resource set is activated and/or deactivated.

The base station may configure the UE to report CSI measurements. Thebase station may configure the UE to provide CSI reports periodically,aperiodically, or semi-persistently. For periodic CSI reporting, the UEmay be configured with a timing and/or periodicity of a plurality of CSIreports. For aperiodic CSI reporting, the base station may request a CSIreport. For example, the base station may command the UE to measure aconfigured CSI-RS resource and provide a CSI report relating to themeasurements. For semi-persistent CSI reporting, the base station mayconfigure the UE to transmit periodically, and selectively activate ordeactivate the periodic reporting. The base station may configure the UEwith a CSI-RS resource set and CSI reports using RRC signaling.

The CSI-RS configuration may comprise one or more parameters indicating,for example, up to 32 antenna ports. The UE may be configured to employthe same OFDM symbols for a downlink CSI-RS and a control resource set(CORESET) when the downlink CSI-RS and CORESET are spatially QCLed andresource elements associated with the downlink CSI-RS are outside of thephysical resource blocks (PRBs) configured for the CORESET. The UE maybe configured to employ the same OFDM symbols for downlink CSI-RS andSS/PBCH blocks when the downlink CSI-RS and SS/PBCH blocks are spatiallyQCLed and resource elements associated with the downlink CSI-RS areoutside of PRBs configured for the SS/PBCH blocks.

Downlink DMRSs may be transmitted by a base station and used by a UE forchannel estimation. For example, the downlink DMRS may be used forcoherent demodulation of one or more downlink physical channels (e.g.,PDSCH). An NR network may support one or more variable and/orconfigurable DMRS patterns for data demodulation. At least one downlinkDMRS configuration may support a front-loaded DMRS pattern. Afront-loaded DMRS may be mapped over one or more OFDM symbols (e.g., oneor two adjacent OFDM symbols). A base station may semi-staticallyconfigure the UE with a number (e.g. a maximum number) of front-loadedDMRSsymbols for PDSCH. A DMRS configuration may support one or more DMRSports. For example, for single user-MIMO, a DMRS configuration maysupport up to eight orthogonal downlink DMRS ports per UE. Formultiuser-MIMO, a DMRS configuration may support up to 4 orthogonaldownlink DMRS ports per UE. A radio network may support (e.g., at leastfor CP-OFDM) a common DMRS structure for downlink and uplink, wherein aDMRS location, a DMRS pattern, and/or a scrambling sequence may be thesame or different. The base station may transmit a downlink DMRS and acorresponding PDSCH using the same precoding matrix. The UE may use theone or more downlink DMRSs for coherent demodulation/channel estimationof the PDSCH.

In an example, a transmitter (e.g., a base station) may use a precodermatrices for a part of a transmission bandwidth. For example, thetransmitter may use a first precoder matrix for a first bandwidth and asecond precoder matrix for a second bandwidth. The first precoder matrixand the second precoder matrix may be different based on the firstbandwidth being different from the second bandwidth. The UE may assumethat a same precoding matrix is used across a set of PRBs. The set ofPRBs may be denoted as a precoding resource block group (PRG).

A PDSCH may comprise one or more layers. The UE may assume that at leastone symbol with DMRS is present on a layer of the one or more layers ofthe PDSCH. A higher layer may configure up to 3 DMRSs for the PDSCH.

Downlink PT-RS may be transmitted by a base station and used by a UE forphase-noise compensation. Whether a downlink PT-RS is present or not maydepend on an RRC configuration. The presence and/or pattern of thedownlink PT-RS may be configured on a UE-specific basis using acombination of RRC signaling and/or an association with one or moreparameters employed for other purposes (e.g., modulation and codingscheme (MCS)), which may be indicated by DCI. When configured, a dynamicpresence of a downlink PT-RS may be associated with one or more DCIparameters comprising at least MCS. An NR network may support aplurality of PT-RS densities defined in the time and/or frequencydomains. When present, a frequency domain density may be associated withat least one configuration of a scheduled bandwidth. The UE may assume asame precoding for a DMRS port and a PT-RS port. A number of PT-RS portsmay be fewer than a number of DMRS ports in a scheduled resource.Downlink PT-RS may be confined in the scheduled time/frequency durationfor the UE. Downlink PT-RS may be transmitted on symbols to facilitatephase tracking at the receiver.

The UE may transmit an uplink DMRS to a base station for channelestimation. For example, the base station may use the uplink DMRS forcoherent demodulation of one or more uplink physical channels. Forexample, the UE may transmit an uplink DMRS with a PUSCH and/or a PUCCH.The uplink DM-RS may span a range of frequencies that is similar to arange of frequencies associated with the corresponding physical channel.The base station may configure the UE with one or more uplink DMRSconfigurations. At least one DMRS configuration may support afront-loaded DMRS pattern. The front-loaded DMRS may be mapped over oneor more OFDM symbols (e.g., one or two adjacent OFDM symbols). One ormore uplink DMRSs may be configured to transmit at one or more symbolsof a PUSCH and/or a PUCCH. The base station may semi-staticallyconfigure the UE with a number (e.g. maximum number) of front-loadedDMRSsymbols for the PUSCH and/or the PUCCH, which the UE may use toschedule a single-symbol DMRS and/or a double-symbol DMRS. An NR networkmay support (e.g., for cyclic prefix orthogonal frequency divisionmultiplexing (CP-OFDM)) a common DMRSstructure for downlink and uplink,wherein a DMRS location, a DMRS pattern, and/or a scrambling sequencefor the DMRS may be the same or different.

A PUSCH may comprise one or more layers, and the UE may transmit atleast one symbol with DMRS present on a layer of the one or more layersof the PUSCH. In an example, a higher layer may configure up to threeDMRSs for the PUSCH.

Uplink PT-RS (which may be used by a base station for phase trackingand/or phase-noise compensation) may or may not be present depending onan RRC configuration of the UE. The presence and/or pattern of uplinkPT-RS may be configured on a UE-specific basis by a combination of RRCsignaling and/or one or more parameters employed for other purposes(e.g., Modulation and Coding Scheme (MCS)), which may be indicated byDCI. When configured, a dynamic presence of uplink PT-RS may beassociated with one or more DCI parameters comprising at least MCS. Aradio network may support a plurality of uplink PT-RS densities definedin time/frequency domain. When present, a frequency domain density maybe associated with at least one configuration of a scheduled bandwidth.The UE may assume a same precoding for a DMRS port and a PT-RS port. Anumber of PT-RS ports may be fewer than a number of DMRS ports in ascheduled resource. For example, uplink PT-RS may be confined in thescheduled time/frequency duration for the UE.

SRS may be transmitted by a UE to a base station for channel stateestimation to support uplink channel dependent scheduling and/or linkadaptation. SRS transmitted by the UE may allow a base station toestimate an uplink channel state at one or more frequencies. A schedulerat the base station may employ the estimated uplink channel state toassign one or more resource blocks for an uplink PUSCH transmission fromthe UE. The base station may semi-statically configure the UE with oneor more SRS resource sets. For an SRS resource set, the base station mayconfigure the UE with one or more SRS resources. An SRS resource setapplicability may be configured by a higher layer (e.g., RRC) parameter.For example, when a higher layer parameter indicates beam management, anSRS resource in a SRS resource set of the one or more SRS resource sets(e.g., with the same/similar time domain behavior, periodic, aperiodic,and/or the like) may be transmitted at a time instant (e.g.,simultaneously). The UE may transmit one or more SRS resources in SRSresource sets. An NR network may support aperiodic, periodic and/orsemi-persistent SRS transmissions. The UE may transmit SRS resourcesbased on one or more trigger types, wherein the one or more triggertypes may comprise higher layer signaling (e.g., RRC) and/or one or moreDCI formats. In an example, at least one DCI format may be employed forthe UE to select at least one of one or more configured SRS resourcesets. An SRS trigger type 0 may refer to an SRS triggered based on ahigher layer signaling. An SRS trigger type 1 may refer to an SRStriggered based on one or more DCI formats. In an example, when PUSCHand SRS are transmitted in a same slot, the UE may be configured totransmit SRS after a transmission of a PUSCH and a corresponding uplinkDMRS.

The base station may semi-statically configure the UE with one or moreSRS configuration parameters indicating at least one of following: a SRSresource configuration identifier; a number of SRS ports; time domainbehavior of an SRS resource configuration (e.g., an indication ofperiodic, semi-persistent, or aperiodic SRS); slot, mini-slot, and/orsubframe level periodicity; offset for a periodic and/or an aperiodicSRS resource; a number of OFDM symbols in an SRS resource; a startingOFDM symbol of an SRS resource; an SRS bandwidth; a frequency hoppingbandwidth; a cyclic shift; and/or an SRSsequence ID.

An antenna port is defined such that the channel over which a symbol onthe antenna port is conveyed can be inferred from the channel over whichanother symbol on the same antenna port is conveyed. If a first symboland a second symbol are transmitted on the same antenna port, thereceiver may infer the channel (e.g., fading gain, multipath delay,and/or the like) for conveying the second symbol on the antenna port,from the channel for conveying the first symbol on the antenna port. Afirst antenna port and a second antenna port may be referred to as quasico-located (QCLed) if one or more large-scale properties of the channelover which a first symbol on the first antenna port is conveyed may beinferred from the channel over which a second symbol on a second antennaport is conveyed. The one or more large-scale properties may comprise atleast one of: a delay spread; a Doppler spread; a Doppler shift; anaverage gain; an average delay; and/or spatial Receiving (Rx)parameters.

Channels that use beamforming require beam management. Beam managementmay comprise beam measurement, beam selection, and beam indication. Abeam may be associated with one or more reference signals. For example,a beam may be identified by one or more beamformed reference signals.The UE may perform downlink beam measurement based on downlink referencesignals (e.g., a channel state information reference signal (CSI-RS))and generate a beam measurement report. The UE may perform the downlinkbeam measurement procedure after an RRC connection is set up with a basestation.

FIG. 11B illustrates an example of channel state information referencesignals (CSI-RSs) that are mapped in the time and frequency domains. Asquare shown in FIG. 11B may span a resource block (RB) within abandwidth of a cell. A base station may transmit one or more RRCmessages comprising CSI-RS resource configuration parameters indicatingone or more CSI-RSs. One or more of the following parameters may beconfigured by higher layer signaling (e.g., RRC and/or MAC signaling)for a CSI-RS resource configuration: a CSI-RS resource configurationidentity, a number of CSI-RS ports, a CSI-RS configuration (e.g., symboland resource element (RE) locations in a subframe), a CSI-RSsubframeconfiguration (e.g., subframe location, offset, and periodicity in aradio frame), a CSI-RS power parameter, a CSI-RSsequence parameter, acode division multiplexing (CDM) type parameter, a frequency density, atransmission comb, quasi co-location (QCL) parameters (e.g.,QCL-scramblingidentity, crs-portscount, mbsfn-subframeconfiglist,csi-rs-configZPid, qcl-csi-rs-configNZPid), and/or other radio resourceparameters.

The three beams illustrated in FIG. 11B may be configured for a UE in aUE-specific configuration. Three beams are illustrated in FIG. 11B (beam#1, beam #2, and beam #3), more or fewer beams may be configured. Beam#1 may be allocated with CSI-RS 1101 that may be transmitted in one ormore subcarriers in an RB of a first symbol. Beam #2 may be allocatedwith CSI-RS 1102 that may be transmitted in one or more subcarriers inan RB of a second symbol. Beam #3 may be allocated with CSI-RS 1103 thatmay be transmitted in one or more subcarriers in an RB of a thirdsymbol. By using frequency division multiplexing (FDM), a base stationmay use other subcarriers in a same RB (for example, those that are notused to transmit CSI-RS 1101) to transmit another CSI-RS associated witha beam for another UE. By using time domain multiplexing (TDM), beamsused for the UE may be configured such that beams for the UE use symbolsfrom beams of other UEs.

CSI-RSs such as those illustrated in FIG. 11B (e.g., CSI-RS 1101, 1102,1103) may be transmitted by the base station and used by the UE for oneor more measurements. For example, the UE may measure a reference signalreceived power (RSRP) of configured CSI-RS resources. The base stationmay configure the UE with a reporting configuration and the UE mayreport the RSRP measurements to a network (for example, via one or morebase stations) based on the reporting configuration. In an example, thebase station may determine, based on the reported measurement results,one or more transmission configuration indication (TCI) statescomprising a number of reference signals. In an example, the basestation may indicate one or more TCI states to the UE (e.g., via an RRCsignaling, a MAC CE, and/or a DCI). The UE may receive a downlinktransmission with a receive (Rx) beam determined based on the one ormore TCI states. In an example, the UE may or may not have a capabilityof beam correspondence. If the UE has the capability of beamcorrespondence, the UE may determine a spatial domain filter of atransmit (Tx) beam based on a spatial domain filter of the correspondingRx beam. If the UE does not have the capability of beam correspondence,the UE may perform an uplink beam selection procedure to determine thespatial domain filter of the Tx beam. The UE may perform the uplink beamselection procedure based on one or more sounding reference signal (SRS)resources configured to the UE by the base station. The base station mayselect and indicate uplink beams for the UE based on measurements of theone or more SRS resources transmitted by the UE.

In a beam management procedure, a UE may assess (e.g., measure) achannel quality of one or more beam pair links, a beam pair linkcomprising a transmitting beam transmitted by a base station and areceiving beam received by the UE. Based on the assessment, the UE maytransmit a beam measurement report indicating one or more beam pairquality parameters comprising, e.g., one or more beam identifications(e.g., a beam index, a reference signal index, or the like), RSRP, aprecoding matrix indicator (PMI), a channel quality indicator (CQI),and/or a rank indicator (RI).

FIG. 12A illustrates examples of three downlink beam managementprocedures: P1, P2, and P3. Procedure P1 may enable a UE measurement ontransmit (Tx) beams of a transmission reception point (TRP) (or multipleTRPs), e.g., to support a selection of one or more base station Tx beamsand/or UE Rx beams (shown as ovals in the top row and bottom row,respectively, of P1). Beamforming at a TRP may comprise a Tx beam sweepfor a set of beams (shown, in the top rows of P1 and P2, as ovalsrotated in a counter-clockwise direction indicated by the dashed arrow).Beamforming at a UE may comprise an Rx beam sweep for a set of beams(shown, in the bottom rows of P1 and P3, as ovals rotated in a clockwisedirection indicated by the dashed arrow). Procedure P2 may be used toenable a UE measurement on Tx beams of a TRP (shown, in the top row ofP2, as ovals rotated in a counter-clockwise direction indicated by thedashed arrow). The UE and/or the base station may perform procedure P2using a smaller set of beams than is used in procedure P1, or usingnarrower beams than the beams used in procedure P1. This may be referredto as beam refinement. The UE may perform procedure P3 for Rx beamdetermination by using the same Tx beam at the base station and sweepingan Rx beam at the UE.

FIG. 12B illustrates examples of three uplink beam managementprocedures: U1, U2, and U3. Procedure U1 may be used to enable a basestation to perform a measurement on Tx beams of a UE, e.g., to support aselection of one or more UE Tx beams and/or base station Rx beams (shownas ovals in the top row and bottom row, respectively, of U1).Beamforming at the UE may include, e.g., a Tx beam sweep from a set ofbeams (shown in the bottom rows of U1 and U3 as ovals rotated in aclockwise direction indicated by the dashed arrow). Beamforming at thebase station may include, e.g., an Rx beam sweep from a set of beams(shown, in the top rows of U1 and U2, as ovals rotated in acounter-clockwise direction indicated by the dashed arrow). Procedure U2may be used to enable the base station to adjust its Rx beam when the UEuses a fixed Tx beam. The UE and/or the base station may performprocedure U2 using a smaller set of beams than is used in procedure P1,or using narrower beams than the beams used in procedure P1. This may bereferred to as beam refinement The UE may perform procedure U3 to adjustits Tx beam when the base station uses a fixed Rx beam.

A UE may initiate a beam failure recovery (BFR) procedure based ondetecting a beam failure. The UE may transmit a BFR request (e.g., apreamble, a UCI, an SR, a MAC CE, and/or the like) based on theinitiating of the BFR procedure. The UE may detect the beam failurebased on a determination that a quality of beam pair link(s) of anassociated control channel is unsatisfactory (e.g., having an error ratehigher than an error rate threshold, a received signal power lower thana received signal power threshold, an expiration of a timer, and/or thelike).

The UE may measure a quality of a beam pair link using one or morereference signals (RSs) comprising one or more SS/PBCH blocks, one ormore CSI-RS resources, and/or one or more demodulation reference signals(DMRSs). A quality of the beam pair link may be based on one or more ofa block error rate (BLER), an RSRP value, a signal to interference plusnoise ratio (SINR) value, a reference signal received quality (RSRQ)value, and/or a CSI value measured on RS resources. The base station mayindicate that an RS resource is quasi co-located (QCLed) with one ormore DM-RSs of a channel (e.g., a control channel, a shared datachannel, and/or the like). The RS resource and the one or more DMRSs ofthe channel may be QCLed when the channel characteristics (e.g., Dopplershift, Doppler spread, average delay, delay spread, spatial Rxparameter, fading, and/or the like) from a transmission via the RSresource to the UE are similar or the same as the channelcharacteristics from a transmission via the channel to the UE.

A network (e.g., a gNB and/or an ng-eNB of a network) and/or the UE mayinitiate a random access procedure. A UE in an RRC_IDLE state and/or anRRC_INACTIVE state may initiate the random access procedure to request aconnection setup to a network. The UE may initiate the random accessprocedure from an RRC_CONNECTED state. The UE may initiate the randomaccess procedure to request uplink resources (e.g., for uplinktransmission of an SR when there is no PUCCH resource available) and/oracquire uplink timing (e.g., when uplink synchronization status isnon-synchronized). The UE may initiate the random access procedure torequest one or more system information blocks (SIBs) (e.g., other systeminformation such as SIB2, SIB3, and/or the like). The UE may initiatethe random access procedure for a beam failure recovery request. Anetwork may initiate a random access procedure for a handover and/or forestablishing time alignment for an SCell addition.

FIG. 13A illustrates a four-step contention-based random accessprocedure. Prior to initiation of the procedure, a base station maytransmit a configuration message 1310 to the UE. The procedureillustrated in FIG. 13A comprises transmission of four messages: a Msg 11311, a Msg 2 1312, a Msg 3 1313, and a Msg 4 1314. The Msg 1 1311 mayinclude and/or be referred to as a preamble (or a random accesspreamble). The Msg 2 1312 may include and/or be referred to as a randomaccess response (RAR).

The configuration message 1310 may be transmitted, for example, usingone or more RRC messages. The one or more RRC messages may indicate oneor more random access channel (RACH) parameters to the UE. The one ormore RACH parameters may comprise at least one of following: generalparameters for one or more random access procedures (e.g.,RACH-configGeneral); cell-specific parameters (e.g., RACH-ConfigCommon);and/or dedicated parameters (e.g., RACH-configDedicated). The basestation may broadcast or multicast the one or more RRC messages to oneor more UEs. The one or more RRC messages may be UE-specific (e.g.,dedicated RRC messages transmitted to a UE in an RRC_CONNECTED stateand/or in an RRC_INACTIVE state). The UE may determine, based on the oneor more RACH parameters, a time-frequency resource and/or an uplinktransmit power for transmission of the Msg 1 1311 and/or the Msg 3 1313.Based on the one or more RACH parameters, the UE may determine areception timing and a downlink channel for receiving the Msg 2 1312 andthe Msg 4 1314.

The one or more RACH parameters provided in the configuration message1310 may indicate one or more Physical RACH (PRACH) occasions availablefor transmission of the Msg 1 1311. The one or more PRACH occasions maybe predefined. The one or more RACH parameters may indicate one or moreavailable sets of one or more PRACH occasions (e.g., prach-ConfigIndex).The one or more RACH parameters may indicate an association between (a)one or more PRACH occasions and (b) one or more reference signals. Theone or more RACH parameters may indicate an association between (a) oneor more preambles and (b) one or more reference signals. The one or morereference signals may be SS/PBCH blocks and/or CSI-RSs. For example, theone or more RACH parameters may indicate a number of SS/PBCH blocksmapped to a PRACH occasion and/or a number of preambles mapped to aSS/PBCH blocks.

The one or more RACH parameters provided in the configuration message1310 may be used to determine an uplink transmit power of Msg 1 1311and/or Msg 3 1313. For example, the one or more RACH parameters mayindicate a reference power for a preamble transmission (e.g., a receivedtarget power and/or an initial power of the preamble transmission).There may be one or more power offsets indicated by the one or more RACHparameters. For example, the one or more RACH parameters may indicate: apower ramping step; a power offset between SSB and CSI-RS; a poweroffset between transmissions of the Msg 1 1311 and the Msg 3 1313;and/or a power offset value between preamble groups. The one or moreRACH parameters may indicate one or more thresholds based on which theUE may determine at least one reference signal (e.g., an SSB and/orCSI-RS) and/or an uplink carrier (e.g., a normal uplink (NUL) carrierand/or a supplemental uplink (SUL) carrier).

The Msg 1 1311 may include one or more preamble transmissions (e.g., apreamble transmission and one or more preamble retransmissions). An RRCmessage may be used to configure one or more preamble groups (e.g.,group A and/or group B). A preamble group may comprise one or morepreambles. The UE may determine the preamble group based on a pathlossmeasurement and/or a size of the Msg 3 1313. The UE may measure an RSRPof one or more reference signals (e.g., SSBs and/or CSI-RSs) anddetermine at least one reference signal having an RSRP above an RSRPthreshold (e.g., rsrp-ThresholdSSB and/or rsrp-ThresholdCSI-RS). The UEmay select at least one preamble associated with the one or morereference signals and/or a selected preamble group, for example, if theassociation between the one or more preambles and the at least onereference signal is configured by an RRC message.

The UE may determine the preamble based on the one or more RACHparameters provided in the configuration message 1310. For example, theUE may determine the preamble based on a pathloss measurement, an RSRPmeasurement, and/or a size of the Msg 3 1313. As another example, theone or more RACH parameters may indicate: a preamble format; a maximumnumber of preamble transmissions; and/or one or more thresholds fordetermining one or more preamble groups (e.g., group A and group B). Abase station may use the one or more RACH parameters to configure the UEwith an association between one or more preambles and one or morereference signals (e.g., SSBs and/or CSI-RSs). If the association isconfigured, the UE may determine the preamble to include in Msg 1 1311based on the association. The Msg 1 1311 may be transmitted to the basestation via one or more PRACH occasions. The UE may use one or morereference signals (e.g., SSBs and/or CSI-RSs) for selection of thepreamble and for determining of the PRACH occasion. One or more RACHparameters (e.g., ra-ssb-OccasionMskIndex and/or ra-OccasionList) mayindicate an association between the PRACH occasions and the one or morereference signals.

The UE may perform a preamble retransmission if no response is receivedfollowing a preamble transmission. The UE may increase an uplinktransmit power for the preamble retransmission. The UE may select aninitial preamble transmit power based on a pathloss measurement and/or atarget received preamble power configured by the network. The UE maydetermine to retransmit a preamble and may ramp up the uplink transmitpower. The UE may receive one or more RACH parameters (e.g.,PREAMBLE_POWER_RAMPING_STEP) indicating a ramping step for the preambleretransmission. The ramping step may be an amount of incrementalincrease in uplink transmit power for a retransmission. The UE may rampup the uplink transmit power if the UE determines a reference signal(e.g., SSB and/or CSI-RS) that is the same as a previous preambletransmission. The UE may count a number of preamble transmissions and/orretransmissions (e.g., PREAMBLE_TRANSMISSION_COUNTER). The UE maydetermine that a random access procedure completed unsuccessfully, forexample, if the number of preamble transmissions exceeds a thresholdconfigured by the one or more RACH parameters (e.g., preambleTransMax).

The Msg 2 1312 received by the UE may include an RAR. In some scenarios,the Msg 2 1312 may include multiple RARs corresponding to multiple UEs.The Msg 2 1312 may be received after or in response to the transmittingof the Msg 1 1311. The Msg 2 1312 may be scheduled on the DL-SCH andindicated on a PDCCH using a random access RNTI (RA-RNTI). The Msg 21312 may indicate that the Msg 1 1311 was received by the base station.The Msg 2 1312 may include a time-alignment command that may be used bythe UE to adjust the UE's transmission timing, a scheduling grant fortransmission of the Msg 3 1313, and/or a Temporary Cell RNTI (TC-RNTI).After transmitting a preamble, the UE may start a time window (e.g.,ra-ResponseWindow) to monitor a PDCCH for the Msg 2 1312. The UE maydetermine when to start the time window based on a PRACH occasion thatthe UE uses to transmit the preamble. For example, the UE may start thetime window one or more symbols after a last symbol of the preamble(e.g., at a first PDCCH occasion from an end of a preambletransmission). The one or more symbols may be determined based on anumerology. The PDCCH may be in a common search space (e.g., aType1-PDCCH common search space) configured by an RRC message. The UEmay identify the RAR based on a Radio Network Temporary Identifier(RNTI). RNTIs may be used depending on one or more events initiating therandom access procedure. The UE may use random access RNTI (RA-RNTI).The RA-RNTI may be associated with PRACH occasions in which the UEtransmits a preamble. For example, the UE may determine the RA-RNTIbased on: an OFDM symbol index; a slot index; a frequency domain index;and/or a UL carrier indicator of the PRACH occasions. An example ofRA-RNTI may be as follows:RA-RNTI=1+s_id+14×t_id+14×80×f_id+14×80×8×ul_carrier_idwhere s_id may be an index of a first OFDM symbol of the PRACH occasion(e.g., 0≤s_id<14), t_id may be an index of a first slot of the PRACHoccasion in a system frame (e.g., 0≤t_id<80), f_id may be an index ofthe PRACH occasion in the frequency domain (e.g., 0≤f_id<8), andul_carrier_id may be a UL carrier used for a preamble transmission(e.g., 0 for an NUL carrier, and 1 for an SUL carrier).The UE may transmit the Msg 3 1313 in response to a successful receptionof the Msg 2 1312 (e.g., using resources identified in the Msg 2 1312).The Msg 3 1313 may be used for contention resolution in, for example,the contention-based random access procedure illustrated in FIG. 13A. Insome scenarios, a plurality of UEs may transmit a same preamble to abase station and the base station may provide an RAR that corresponds toa UE. Collisions may occur if the plurality of UEs interpret the RAR ascorresponding to themselves. Contention resolution (e.g., using the Msg3 1313 and the Msg 4 1314) may be used to increase the likelihood thatthe UE does not incorrectly use an identity of another the UE. Toperform contention resolution, the UE may include a device identifier inthe Msg 3 1313 (e.g., a C-RNTI if assigned, a TC-RNTI included in theMsg 2 1312, and/or any other suitable identifier).

The Msg 4 1314 may be received after or in response to the transmittingof the Msg 3 1313. If a C-RNTI was included in the Msg 3 1313, the basestation will address the UE on the PDCCH using the C-RNTI. If the UE'sunique C-RNTI is detected on the PDCCH, the random access procedure isdetermined to be successfully completed. If a TC-RNTI is included in theMsg 3 1313 (e.g., if the UE is in an RRC_IDLE state or not otherwiseconnected to the base station), Msg 4 1314 will be received using aDL-SCH associated with the TC-RNTI. If a MAC PDU is successfully decodedand a MAC PDU comprises the UE contention resolution identity MAC CEthat matches or otherwise corresponds with the CCCH SDU sent (e.g.,transmitted) in Msg 3 1313, the UE may determine that the contentionresolution is successful and/or the UE may determine that the randomaccess procedure is successfully completed.

The UE may be configured with a supplementary uplink (SUL) carrier and anormal uplink (NUL) carrier. An initial access (e.g., random accessprocedure) may be supported in an uplink carrier. For example, a basestation may configure the UE with two separate RACH configurations: onefor an SUL carrier and the other for an NUL carrier. For random accessin a cell configured with an SUL carrier, the network may indicate whichcarrier to use (NUL or SUL). The UE may determine the SUL carrier, forexample, if a measured quality of one or more reference signals is lowerthan a broadcast threshold. Uplink transmissions of the random accessprocedure (e.g., the Msg 1 1311 and/or the Msg 3 1313) may remain on theselected carrier. The UE may switch an uplink carrier during the randomaccess procedure (e.g., between the Msg 1 1311 and the Msg 3 1313) inone or more cases. For example, the UE may determine and/or switch anuplink carrier for the Msg 1 1311 and/or the Msg 3 1313 based on achannel clear assessment (e.g., a listen-before-talk).

FIG. 13B illustrates a two-step contention-free random access procedure.Similar to the four-step contention-based random access procedureillustrated in FIG. 13A, a base station may, prior to initiation of theprocedure, transmit a configuration message 1320 to the UE. Theconfiguration message 1320 may be analogous in some respects to theconfiguration message 1310. The procedure illustrated in FIG. 13Bcomprises transmission of two messages: a Msg 1 1321 and a Msg 2 1322.The Msg 1 1321 and the Msg 2 1322 may be analogous in some respects tothe Msg 1 1311 and a Msg 2 1312 illustrated in FIG. 13A, respectively.As will be understood from FIGS. 13A and 13B, the contention-free randomaccess procedure may not include messages analogous to the Msg 3 1313and/or the Msg 4 1314.

The contention-free random access procedure illustrated in FIG. 13B maybe initiated for a beam failure recovery, other SI request, SCelladdition, and/or handover. For example, a base station may indicate orassign to the UE the preamble to be used for the Msg 1 1321. The UE mayreceive, from the base station via PDCCH and/or RRC, an indication of apreamble (e.g., ra-PreambleIndex).

After transmitting a preamble, the UE may start a time window (e.g.,ra-ResponseWindow) to monitor a PDCCH for the RAR. In the event of abeam failure recovery request, the base station may configure the UEwith a separate time window and/or a separate PDCCH in a search spaceindicated by an RRC message (e.g., recoverySearchSpaceId). The UE maymonitor for a PDCCH transmission addressed to a Cell RNTI (C-RNTI) onthe search space. In the contention-free random access procedureillustrated in FIG. 13B, the UE may determine that a random accessprocedure successfully completes after or in response to transmission ofMsg 1 1321 and reception of a corresponding Msg 2 1322. The UE maydetermine that a random access procedure successfully completes, forexample, if a PDCCH transmission is addressed to a C-RNTI. The UE maydetermine that a random access procedure successfully completes, forexample, if the UE receives an RAR comprising a preamble identifiercorresponding to a preamble transmitted by the UE and/or the RARcomprises a MAC sub-PDU with the preamble identifier. The UE maydetermine the response as an indication of an acknowledgement for an SIrequest.

FIG. 13C illustrates another two-step random access procedure. Similarto the random access procedures illustrated in FIGS. 13A and 13B, a basestation may, prior to initiation of the procedure, transmit aconfiguration message 1330 to the UE. The configuration message 1330 maybe analogous in some respects to the configuration message 1310 and/orthe configuration message 1320. The procedure illustrated in FIG. 13Ccomprises transmission of two messages: a Msg A 1331 and a Msg B 1332.

Msg A 1331 may be transmitted in an uplink transmission by the UE. Msg A1331 may comprise one or more transmissions of a preamble 1341 and/orone or more transmissions of a transport block 1342. The transport block1342 may comprise contents that are similar and/or equivalent to thecontents of the Msg 3 1313 illustrated in FIG. 13A. The transport block1342 may comprise UCI (e.g., an SR, a HARQ ACK/NACK, and/or the like).The UE may receive the Msg B 1332 after or in response to transmittingthe Msg A 1331. The Msg B 1332 may comprise contents that are similarand/or equivalent to the contents of the Msg 2 1312 (e.g., an RAR)illustrated in FIGS. 13A and 13B and/or the Msg 4 1314 illustrated inFIG. 13A.

The UE may initiate the two-step random access procedure in FIG. 13C forlicensed spectrum and/or unlicensed spectrum. The UE may determine,based on one or more factors, whether to initiate the two-step randomaccess procedure. The one or more factors may be: a radio accesstechnology in use (e.g., LTE, NR, and/or the like); whether the UE hasvalid TA or not; a cell size; the UE's RRC state; a type of spectrum(e.g., licensed vs. unlicensed); and/or any other suitable factors.

The UE may determine, based on two-step RACH parameters included in theconfiguration message 1330, a radio resource and/or an uplink transmitpower for the preamble 1341 and/or the transport block 1342 included inthe Msg A 1331. The RACH parameters may indicate a modulation and codingschemes (MCS), a time-frequency resource, and/or a power control for thepreamble 1341 and/or the transport block 1342. A time-frequency resourcefor transmission of the preamble 1341 (e.g., a PRACH) and atime-frequency resource for transmission of the transport block 1342(e.g., a PUSCH) may be multiplexed using FDM, TDM, and/or CDM. The RACHparameters may enable the UE to determine a reception timing and adownlink channel for monitoring for and/or receiving Msg B 1332.

The transport block 1342 may comprise data (e.g., delay-sensitive data),an identifier of the UE, security information, and/or device information(e.g., an International Mobile Subscriber Identity (IMSI)). The basestation may transmit the Msg B 1332 as a response to the Msg A 1331. TheMsg B 1332 may comprise at least one of following: a preambleidentifier; a timing advance command; a power control command; an uplinkgrant (e.g., a radio resource assignment and/or an MCS); a UE identifierfor contention resolution; and/or an RNTI (e.g., a C-RNTI or a TC-RNTI).The UE may determine that the two-step random access procedure issuccessfully completed if: a preamble identifier in the Msg B 1332 ismatched to a preamble transmitted by the UE; and/or the identifier ofthe UE in Msg B 1332 is matched to the identifier of the UE in the Msg A1331 (e.g., the transport block 1342).

A UE and a base station may exchange control signaling. The controlsignaling may be referred to as L1/L2 control signaling and mayoriginate from the PHY layer (e.g., layer 1) and/or the MAC layer (e.g.,layer 2). The control signaling may comprise downlink control signalingtransmitted from the base station to the UE and/or uplink controlsignaling transmitted from the UE to the base station.

The downlink control signaling may comprise: a downlink schedulingassignment; an uplink scheduling grant indicating uplink radio resourcesand/or a transport format; a slot format information; a preemptionindication; a power control command; and/or any other suitablesignaling. The UE may receive the downlink control signaling in apayload transmitted by the base station on a physical downlink controlchannel (PDCCH). The payload transmitted on the PDCCH may be referred toas downlink control information (DCI). In some scenarios, the PDCCH maybe a group common PDCCH (GC-PDCCH) that is common to a group of UEs.

A base station may attach one or more cyclic redundancy check (CRC)parity bits to a DCI in order to facilitate detection of transmissionerrors. When the DCI is intended for a UE (or a group of the UEs), thebase station may scramble the CRC parity bits with an identifier of theUE (or an identifier of the group of the UEs). Scrambling the CRC paritybits with the identifier may comprise Modulo-2 addition (or an exclusiveOR operation) of the identifier value and the CRC parity bits. Theidentifier may comprise a 16-bit value of a radio network temporaryidentifier (RNTI).

DCIs may be used for different purposes. A purpose may be indicated bythe type of RNTI used to scramble the CRC parity bits. For example, aDCI having CRC parity bits scrambled with a paging RNTI (P-RNTI) mayindicate paging information and/or a system information changenotification. The P-RNTI may be predefined as “FFFE” in hexadecimal. ADCI having CRC parity bits scrambled with a system information RNTI(SI-RNTI) may indicate a broadcast transmission of the systeminformation. The SI-RNTI may be predefined as “FFFF” in hexadecimal. ADCI having CRC parity bits scrambled with a random access RNTI (RA-RNTI)may indicate a random access response (RAR). A DCI having CRC paritybits scrambled with a cell RNTI (C-RNTI) may indicate a dynamicallyscheduled unicast transmission and/or a triggering of PDCCH-orderedrandom access. A DCI having CRC parity bits scrambled with a temporarycell RNTI (TC-RNTI) may indicate a contention resolution (e.g., a Msg 3analogous to the Msg 3 1313 illustrated in FIG. 13A). Other RNTIsconfigured to the UE by a base station may comprise a ConfiguredScheduling RNTI (CS-RNTI), a Transmit Power Control-PUCCH RNTI(TPC-PUCCH-RNTI), a Transmit Power Control-PUSCH RNTI (TPC-PUSCH-RNTI),a Transmit Power Control-SRS RNTI (TPC-SRS-RNTI), an Interruption RNTI(INT-RNTI), a Slot Format Indication RNTI (SFI-RNTI), a Semi-PersistentCSI RNTI (SP-CSI-RNTI), a Modulation and Coding Scheme Cell RNTI(MCS-C-RNTI), and/or the like.

Depending on the purpose and/or content of a DCI, the base station maytransmit the DCIs with one or more DCI formats. For example, DCI format0_0 may be used for scheduling of PUSCH in a cell. DCI format 0_0 may bea fallback DCI format (e.g., with compact DCI payloads). DCI format 0_1may be used for scheduling of PUSCH in a cell (e.g., with more DCIpayloads than DCI format 0_0). DCI format 1_0 may be used for schedulingof PDSCH in a cell. DCI format 1_0 may be a fallback DCI format (e.g.,with compact DCI payloads). DCI format 1_1 may be used for scheduling ofPDSCH in a cell (e.g., with more DCI payloads than DCI format 1_0). DCIformat 2_0 may be used for providing a slot format indication to a groupof UEs. DCI format 2_1 may be used for notifying a group of UEs of aphysical resource block and/or OFDM symbol where the UE may assume notransmission is intended to the UE. DCI format 2_2 may be used fortransmission of a transmit power control (TPC) command for PUCCH orPUSCH. DCI format 2_3 may be used for transmission of a group of TPCcommands for SRS transmissions by one or more UEs. DCI format(s) for newfunctions may be defined in future releases. DCI formats may havedifferent DCI sizes, or may share the same DCI size.

After scrambling a DCI with a RNTI, the base station may process the DCIwith channel coding (e.g., polar coding), rate matching, scramblingand/or QPSK modulation. A base station may map the coded and modulatedDCI on resource elements used and/or configured for a PDCCH. Based on apayload size of the DCI and/or a coverage of the base station, the basestation may transmit the DCI via a PDCCH occupying a number ofcontiguous control channel elements (CCEs). The number of the contiguousCCEs (referred to as aggregation level) may be 1, 2, 4, 8, 16, and/orany other suitable number. A CCE may comprise a number (e.g., 6) ofresource-element groups (REGs). A REG may comprise a resource block inan OFDM symbol. The mapping of the coded and modulated DCI on theresource elements may be based on mapping of CCEs and REGs (e.g.,CCE-to-REG mapping).

FIG. 14A illustrates an example of CORESET configurations for abandwidth part. The base station may transmit a DCI via a PDCCH on oneor more control resource sets (CORESETs). A CORESET may comprise atime-frequency resource in which the UE tries to decode a DCI using oneor more search spaces. The base station may configure a CORESET in thetime-frequency domain. In the example of FIG. 14A, a first CORESET 1401and a second CORESET 1402 occur at the first symbol in a slot. The firstCORESET 1401 overlaps with the second CORESET 1402 in the frequencydomain. A third CORESET 1403 occurs at a third symbol in the slot. Afourth CORESET 1404 occurs at the seventh symbol in the slot. CORESETsmay have a different number of resource blocks in frequency domain.

FIG. 14B illustrates an example of a CCE-to-REG mapping for DCItransmission on a CORESET and PDCCH processing. The CCE-to-REG mappingmay be an interleaved mapping (e.g., for the purpose of providingfrequency diversity) or a non-interleaved mapping (e.g., for thepurposes of facilitating interference coordination and/orfrequency-selective transmission of control channels). The base stationmay perform different or same CCE-to-REG mapping on different CORESETs.A CORESET may be associated with a CCE-to-REG mapping by RRCconfiguration. A CORESET may be configured with an antenna port quasico-location (QCL) parameter. The antenna port QCL parameter may indicateQCL information of a demodulation reference signal (DMRS) for PDCCHreception in the CORESET.

The base station may transmit, to the UE, RRC messages comprisingconfiguration parameters of one or more CORESETs and one or more searchspace sets. The configuration parameters may indicate an associationbetween a search space set and a CORESET. A search space set maycomprise a set of PDCCH candidates formed by CCEs at a given aggregationlevel. The configuration parameters may indicate: a number of PDCCHcandidates to be monitored per aggregation level; a PDCCH monitoringperiodicity and a PDCCH monitoring pattern; one or more DCI formats tobe monitored by the UE; and/or whether a search space set is a commonsearch space set or a UE-specific search space set. A set of CCEs in thecommon search space set may be predefined and known to the UE. A set ofCCEs in the UE-specific search space set may be configured based on theUE's identity (e.g., C-RNTI).

As shown in FIG. 14B, the UE may determine a time-frequency resource fora CORESET based on RRC messages. The UE may determine a CCE-to-REGmapping (e.g., interleaved or non-interleaved, and/or mappingparameters) for the CORESET based on configuration parameters of theCORESET. The UE may determine a number (e.g., at most 10) of searchspace sets configured on the CORESET based on the RRC messages. The UEmay monitor a set of PDCCH candidates according to configurationparameters of a search space set. The UE may monitor a set of PDCCHcandidates in one or more CORESETs for detecting one or more DCIs.Monitoring may comprise decoding one or more PDCCH candidates of the setof the PDCCH candidates according to the monitored DCI formats.Monitoring may comprise decoding a DCI content of one or more PDCCHcandidates with possible (or configured) PDCCH locations, possible (orconfigured) PDCCH formats (e.g., number of CCEs, number of PDCCHcandidates in common search spaces, and/or number of PDCCH candidates inthe UE-specific search spaces) and possible (or configured) DCI formats.The decoding may be referred to as blind decoding. The UE may determinea DCI as valid for the UE, in response to CRC checking (e.g., scrambledbits for CRC parity bits of the DCI matching a RNTI value). The UE mayprocess information contained in the DCI (e.g., a scheduling assignment,an uplink grant, power control, a slot format indication, a downlinkpreemption, and/or the like).

The UE may transmit uplink control signaling (e.g., uplink controlinformation (UCI)) to a base station. The uplink control signaling maycomprise hybrid automatic repeat request (HARQ) acknowledgements forreceived DL-SCH transport blocks. The UE may transmit the HARQacknowledgements after receiving a DL-SCH transport block. Uplinkcontrol signaling may comprise channel state information (CSI)indicating channel quality of a physical downlink channel. The UE maytransmit the CSI to the base station. The base station, based on thereceived CSI, may determine transmission format parameters (e.g.,comprising multi-antenna and beamforming schemes) for a downlinktransmission. Uplink control signaling may comprise scheduling requests(SR). The UE may transmit an SR indicating that uplink data is availablefor transmission to the base station. The UE may transmit a UCI (e.g.,HARQ acknowledgements (HARQ-ACK), CSI report, SR, and the like) via aphysical uplink control channel (PUCCH) or a physical uplink sharedchannel (PUSCH). The UE may transmit the uplink control signaling via aPUCCH using one of several PUCCH formats.

There may be five PUCCH formats and the UE may determine a PUCCH formatbased on a size of the UCI (e.g., a number of uplink symbols of UCItransmission and a number of UCI bits). PUCCH format 0 may have a lengthof one or two OFDM symbols and may include two or fewer bits. The UE maytransmit UCI in a PUCCH resource using PUCCH format 0 if thetransmission is over one or two symbols and the number of HARQ-ACKinformation bits with positive or negative SR (HARQ-ACK/SR bits) is oneor two. PUCCH format 1 may occupy a number between four and fourteenOFDM symbols and may include two or fewer bits. The UE may use PUCCHformat 1 if the transmission is four or more symbols and the number ofHARQ-ACK/SR bits is one or two. PUCCH format 2 may occupy one or twoOFDM symbols and may include more than two bits. The UE may use PUCCHformat 2 if the transmission is over one or two symbols and the numberof UCI bits is two or more. PUCCH format 3 may occupy a number betweenfour and fourteen OFDM symbols and may include more than two bits. TheUE may use PUCCH format 3 if the transmission is four or more symbols,the number of UCI bits is two or more and PUCCH resource does notinclude an orthogonal cover code. PUCCH format 4 may occupy a numberbetween four and fourteen OFDM symbols and may include more than twobits. The UE may use PUCCH format 4 if the transmission is four or moresymbols, the number of UCI bits is two or more and the PUCCH resourceincludes an orthogonal cover code.

The base station may transmit configuration parameters to the UE for aplurality of PUCCH resource sets using, for example, an RRC message. Theplurality of PUCCH resource sets (e.g., up to four sets) may beconfigured on an uplink BWP of a cell. A PUCCH resource set may beconfigured with a PUCCH resource set index, a plurality of PUCCHresources with a PUCCH resource being identified by a PUCCH resourceidentifier (e.g., pucch-Resourceid), and/or a number (e.g. a maximumnumber) of UCI information bits the UE may transmit using one of theplurality of PUCCH resources in the PUCCH resource set. When configuredwith a plurality of PUCCH resource sets, the UE may select one of theplurality of PUCCH resource sets based on a total bit length of the UCIinformation bits (e.g., HARQ-ACK, SR, and/or CSI). If the total bitlength of UCI information bits is two or fewer, the UE may select afirst PUCCH resource set having a PUCCH resource set index equal to “0”.If the total bit length of UCI information bits is greater than two andless than or equal to a first configured value, the UE may select asecond PUCCH resource set having a PUCCH resource set index equal to“1”. If the total bit length of UCI information bits is greater than thefirst configured value and less than or equal to a second configuredvalue, the UE may select a third PUCCH resource set having a PUCCHresource set index equal to “2”. If the total bit length of UCIinformation bits is greater than the second configured value and lessthan or equal to a third value (e.g., 1406), the UE may select a fourthPUCCH resource set having a PUCCH resource set index equal to “3”.

After determining a PUCCH resource set from a plurality of PUCCHresource sets, the UE may determine a PUCCH resource from the PUCCHresource set for UCI (HARQ-ACK, CSI, and/or SR) transmission. The UE maydetermine the PUCCH resource based on a PUCCH resource indicator in aDCI (e.g., with a DCI format 1_0 or DCI for 1_1) received on a PDCCH. Athree-bit PUCCH resource indicator in the DCI may indicate one of eightPUCCH resources in the PUCCH resource set. Based on the PUCCH resourceindicator, the UE may transmit the UCI (HARQ-ACK, CSI and/or SR) using aPUCCH resource indicated by the PUCCH resource indicator in the DCI.

FIG. 15 illustrates an example of a wireless device 1502 incommunication with a base station 1504 in accordance with embodiments ofthe present disclosure. The wireless device 1502 and base station 1504may be part of a mobile communication network, such as the mobilecommunication network 100 illustrated in FIG. 1A, the mobilecommunication network 150 illustrated in FIG. 1B, or any othercommunication network. Only one wireless device 1502 and one basestation 1504 are illustrated in FIG. 15 , but it will be understood thata mobile communication network may include more than one UE and/or morethan one base station, with the same or similar configuration as thoseshown in FIG. 15 .

The base station 1504 may connect the wireless device 1502 to a corenetwork (not shown) through radio communications over the air interface(or radio interface) 1506. The communication direction from the basestation 1504 to the wireless device 1502 over the air interface 1506 isknown as the downlink, and the communication direction from the wirelessdevice 1502 to the base station 1504 over the air interface is known asthe uplink. Downlink transmissions may be separated from uplinktransmissions using FDD, TDD, and/or some combination of the twoduplexing techniques.

In the downlink, data to be sent to the wireless device 1502 from thebase station 1504 may be provided to the processing system 1508 of thebase station 1504. The data may be provided to the processing system1508 by, for example, a core network. In the uplink, data to be sent tothe base station 1504 from the wireless device 1502 may be provided tothe processing system 1518 of the wireless device 1502. The processingsystem 1508 and the processing system 1518 may implement layer 3 andlayer 2 OSI functionality to process the data for transmission. Layer 2may include an SDAP layer, a PDCP layer, an RLC layer, and a MAC layer,for example, with respect to FIG. 2A, FIG. 2B, FIG. 3 , and FIG. 4A.Layer 3 may include an RRC layer as with respect to FIG. 2B.

After being processed by processing system 1508, the data to be sent tothe wireless device 1502 may be provided to a transmission processingsystem 1510 of base station 1504. Similarly, after being processed bythe processing system 1518, the data to be sent to base station 1504 maybe provided to a transmission processing system 1520 of the wirelessdevice 1502. The transmission processing system 1510 and thetransmission processing system 1520 may implement layer 1 OSIfunctionality. Layer 1 may include a PHY layer with respect to FIG. 2A,FIG. 2B, FIG. 3 , and FIG. 4A. For transmit processing, the PHY layermay perform, for example, forward error correction coding of transportchannels, interleaving, rate matching, mapping of transport channels tophysical channels, modulation of physical channel, multiple-inputmultiple-output (MIMO) or multi-antenna processing, and/or the like.

At the base station 1504, a reception processing system 1512 may receivethe uplink transmission from the wireless device 1502. At the wirelessdevice 1502, a reception processing system 1522 may receive the downlinktransmission from base station 1504. The reception processing system1512 and the reception processing system 1522 may implement layer 1 OSIfunctionality. Layer 1 may include a PHY layer with respect to FIG. 2A,FIG. 2B, FIG. 3 , and FIG. 4A. For receive processing, the PHY layer mayperform, for example, error detection, forward error correctiondecoding, deinterleaving, demapping of transport channels to physicalchannels, demodulation of physical channels, MIMO or multi-antennaprocessing, and/or the like.

As shown in FIG. 15 , a wireless device 1502 and the base station 1504may include multiple antennas. The multiple antennas may be used toperform one or more MIMO or multi-antenna techniques, such as spatialmultiplexing (e.g., single-user MIMO or multi-user MIMO),transmit/receive diversity, and/or beamforming. In other examples, thewireless device 1502 and/or the base station 1504 may have a singleantenna.

The processing system 1508 and the processing system 1518 may beassociated with a memory 1514 and a memory 1524, respectively. Memory1514 and memory 1524 (e.g., one or more non-transitory computer readablemediums) may store computer program instructions or code that may beexecuted by the processing system 1508 and/or the processing system 1518to carry out one or more of the functionalities discussed in the presentapplication. Although not shown in FIG. 15 , the transmission processingsystem 1510, the transmission processing system 1520, the receptionprocessing system 1512, and/or the reception processing system 1522 maybe coupled to a memory (e.g., one or more non-transitory computerreadable mediums) storing computer program instructions or code that maybe executed to carry out one or more of their respectivefunctionalities.

The processing system 1508 and/or the processing system 1518 maycomprise one or more controllers and/or one or more processors. The oneor more controllers and/or one or more processors may comprise, forexample, a general-purpose processor, a digital signal processor (DSP),a microcontroller, an application specific integrated circuit (ASIC), afield programmable gate array (FPGA) and/or other programmable logicdevice, discrete gate and/or transistor logic, discrete hardwarecomponents, an on-board unit, or any combination thereof. The processingsystem 1508 and/or the processing system 1518 may perform at least oneof signal coding/processing, data processing, power control,input/output processing, and/or any other functionality that may enablethe wireless device 1502 and the base station 1504 to operate in awireless environment.

The processing system 1508 and/or the processing system 1518 may beconnected to one or more peripherals 1516 and one or more peripherals1526, respectively. The one or more peripherals 1516 and the one or moreperipherals 1526 may include software and/or hardware that providefeatures and/or functionalities, for example, a speaker, a microphone, akeypad, a display, a touchpad, a power source, a satellite transceiver,a universal serial bus (USB) port, a hands-free headset, a frequencymodulated (FM) radio unit, a media player, an Internet browser, anelectronic control unit (e.g., for a motor vehicle), and/or one or moresensors (e.g., an accelerometer, a gyroscope, a temperature sensor, aradar sensor, a lidar sensor, an ultrasonic sensor, a light sensor, acamera, and/or the like). The processing system 1508 and/or theprocessing system 1518 may receive user input data from and/or provideuser output data to the one or more peripherals 1516 and/or the one ormore peripherals 1526. The processing system 1518 in the wireless device1502 may receive power from a power source and/or may be configured todistribute the power to the other components in the wireless device1502. The power source may comprise one or more sources of power, forexample, a battery, a solar cell, a fuel cell, or any combinationthereof. The processing system 1508 and/or the processing system 1518may be connected to a GPS chipset 1517 and a GPS chipset 1527,respectively. The GPS chipset 1517 and the GPS chipset 1527 may beconfigured to provide geographic location information of the wirelessdevice 1502 and the base station 1504, respectively.

FIG. 16A illustrates an example structure for uplink transmission. Abaseband signal representing a physical uplink shared channel mayperform one or more functions. The one or more functions may comprise atleast one of: scrambling; modulation of scrambled bits to generatecomplex-valued symbols; mapping of the complex-valued modulation symbolsonto one or several transmission layers; transform precoding to generatecomplex-valued symbols; precoding of the complex-valued symbols; mappingof precoded complex-valued symbols to resource elements; generation ofcomplex-valued time-domain Single Carrier-Frequency Division MultipleAccess (SC-FDMA) or CP-OFDM signal for an antenna port; and/or the like.In an example, when transform precoding is enabled, a SC-FDMA signal foruplink transmission may be generated. In an example, when transformprecoding is not enabled, an CP-OFDM signal for uplink transmission maybe generated by FIG. 16A. These functions are illustrated as examplesand it is anticipated that other mechanisms may be implemented invarious embodiments.

FIG. 16B illustrates an example structure for modulation andup-conversion of a baseband signal to a carrier frequency. The basebandsignal may be a complex-valued SC-FDMA or CP-OFDM baseband signal for anantenna port and/or a complex-valued Physical Random Access Channel(PRACH) baseband signal. Filtering may be employed prior totransmission.

FIG. 16C illustrates an example structure for downlink transmissions. Abaseband signal representing a physical downlink channel may perform oneor more functions. The one or more functions may comprise: scrambling ofcoded bits in a codeword to be transmitted on a physical channel;modulation of scrambled bits to generate complex-valued modulationsymbols; mapping of the complex-valued modulation symbols onto one orseveral transmission layers; precoding of the complex-valued modulationsymbols on a layer for transmission on the antenna ports; mapping ofcomplex-valued modulation symbols for an antenna port to resourceelements; generation of complex-valued time-domain OFDM signal for anantenna port; and/or the like. These functions are illustrated asexamples and it is anticipated that other mechanisms may be implementedin various embodiments.

FIG. 16D illustrates another example structure for modulation andup-conversion of a baseband signal to a carrier frequency. The basebandsignal may be a complex-valued OFDM baseband signal for an antenna port.Filtering may be employed prior to transmission.

A wireless device may receive from a base station one or more messages(e.g. RRC messages) comprising configuration parameters of a pluralityof cells (e.g. primary cell, secondary cell). The wireless device maycommunicate with at least one base station (e.g. two or more basestations in dual-connectivity) via the plurality of cells. The one ormore messages (e.g. as a part of the configuration parameters) maycomprise parameters of physical, MAC, RLC, PCDP, SDAP, RRC layers forconfiguring the wireless device. For example, the configurationparameters may comprise parameters for configuring physical and MAClayer channels, bearers, etc. For example, the configuration parametersmay comprise parameters indicating values of timers for physical, MAC,RLC, PCDP, SDAP, RRC layers, and/or communication channels.

A timer may begin running once it is started and continue running untilit is stopped or until it expires. A timer may be started if it is notrunning or restarted if it is running. A timer may be associated with avalue (e.g. the timer may be started or restarted from a value or may bestarted from zero and expire once it reaches the value). The duration ofa timer may not be updated until the timer is stopped or expires (e.g.,due to BWP switching). A timer may be used to measure a timeperiod/window for a process. When the specification refers to animplementation and procedure related to one or more timers, it will beunderstood that there are multiple ways to implement the one or moretimers. For example, it will be understood that one or more of themultiple ways to implement a timer may be used to measure a timeperiod/window for the procedure. For example, a random access responsewindow timer may be used for measuring a window of time for receiving arandom access response. In an example, instead of starting and expiry ofa random access response window timer, the time difference between twotime stamps may be used. When a timer is restarted, a process formeasurement of time window may be restarted. Other exampleimplementations may be provided to restart a measurement of a timewindow.

A UE-RRC layer may initiate an RRC connection establishment procedure,an RRC connection resume procedure, or an RRC connectionre-establishment procedure. Based on initiating the RRC connectionestablishment procedure or the RRC connection resume procedure, the UEmay perform one or more procedures:

-   -   performing a unified access control procedure for access attempt        on a serving cell;    -   applying default configurations parameters and        configurations/parameters provided by SIB1, for example, based        on the access attempt being allowed, applying default        configurations and configurations/parameters provided by SIB1;    -   starting a timer to supervise those RRC procedures;    -   performing sending a random access preamble to the serving cell,        for example, based on the access attempt being allowed;    -   sending an RRC request message to the serving cell, for example,        based on determining a reception of a random access response        being successful, sending an RRC request message to the serving        cell;    -   receiving an RRC response message or an RRC reject message from        the serving cell; or    -   sending an RRC complete message, for example, based on receiving        the RRC response message, sending an RRC complete message.

-   For the RRC connection re-establishment procedure, the UE may not    perform the unified access procedure.

For initiating those RRC procedures, the UE-RRC layer may use parametersin a received SIB1. The UE-RRC layer may use L1 parameter values and atime alignment timer in the SIB1. The UE-RRC layer may use UAC barringinformation in the SIB1 to perform the unified access control procedure.Based on the unified access control procedure, the UE-RRC layer maydetermine whether the access attempt of those RRC procedures is barredor allowed. Based on the determining the access attempt is allowed, theUE-RRC layer may determine send an RRC request message to a base stationwhere the RRC request message may be an RRC setup request message, anRRC resume request message, or an RRC re-establishment procedure. TheUE-NAS layer may or may not provide S-TMSI as an UE identity. The UE-RRClayer may set an UE identity in the RRC request message.

For the RRC setup request message, the UE may initiate an RRC connectionestablishment procedure. Based on initiating the RRC connectionestablishment procedure, the UE-RRC layer may set the UE identity toS-TMSI if the UE-NAS layer provides the S-TMSI. Otherwise, the UE-RRClayer may draw a 39-bit random value and set the UE identity to therandom value. For the RRC resume request message, the UE-RRC layer mayset the UE identity to resume identity stored. For the RRCreestablishment request message, the UE-RRC layer may set the UEidentity to C-RNTI used in the source PCell. The UE-NAS layer mayprovide an establishment cause (e.g., UE-NAS layer). The UE-RRC layermay set the establishment cause for the RRC request message.

For the RRC resume request message, the UE may initiate an RRCconnection resume procedure. Based on initiating the RRC connectionresume procedure, the UE-RRC layer may restore stored configurationparameters and stored security keys from the stored UE inactive AScontext. Based on the security keys, the UE-RRC layer may set a resumeMAC-I value to the 16 least significant bits of the MAC-I calculatedbased on variable resume MAC input, security key of integrity protectionfor RRC layer in a UE inactive AS context, the previous configuredintegrity protection algorithm, and other security parameters (e.g.,count, bearer and direction). The variable resume MAC input may comprisephysical cell identity and C-RNTI of a source cell, and cell identity ofa target cell. The UE-RRC layer may include the resume MAC-I in the RRCresume request message. Based on the security keys, the UE-RRC layerderive new security keys for integrity protection and ciphering, andconfigure lower layers (e.g. PDCP layer) to apply them. The UE-RRC layermay re-establish PDCP entities for SRB1 and resume SRB1.

For the RRC reestablishment request message, the UE may initiate an RRCconnection reestablishment procedure. Based on initiating the RRCconnection reestablishment procedure, the UE-RRC layer may contain thephysical cell identity of the source PCell and a short MAC-I in the RRCreestablishment message. The UE-RRC layer may set the short MAC-I to the16 east significant bits of the MAC-I calculated based on variable shortMAC input, security key of integrity protection for RRC layer and theintegrity protection algorithm, which was used in a source PCell or thePCell in which the trigger for the reestablishment occurred, and othersecurity parameters (e.g., count, bearer and direction). The variableshort MAC input may comprise physical cell identity and C-RNTI of asource cell, and cell identity of a target cell. The UE-RRC layer mayre-establish PDCP entities and RLC entities for SRB1 and apply a defaultSRB1 configuration parameters for SRB1. The UE-RRC layer may configurelower layers (e.g. PDCP layer) to suspend integrity protection andciphering for SRB1 and resume SRB1.

A UE-RRC layer may send an RRC request message to lower layers (e.g.,PDCP layer, RLC layer, MAC layer and/or PHY layer) for transmission.

A UE-RRC layer may receive an RRC setup message in response to an RRCresume request message or an RRC reestablishment request message. Basedon the RRC setup message, the UE-RRC layer may discard any sorted AScontext, suspend configuration parameters and any current AS securitycontext. The UE-RRC layer may release radio resources for allestablished RBs except SRB0, including release of the RLC entities, ofthe associated PDCP entities and of SDAP. The UE-RRC layer may releasethe RRC configuration except for default L1 parameter values, defaultMAC cell group configuration and CCCH configuration. The UE-RRC layermay indicate to upper layers (e.g., NAS layer) fallback of the RRCconnection. The UE-RRC layer may stop timer T380 if running where thetimer T380 is periodic RNA update timer.

A UE-RRC layer may receive an RRC setup message in response to an RRCsetup request message, an RRC resume request message or an RRCreestablishment request message. The RRC setup message may comprise acell group configurations parameters and a radio bearer configurationparameters. The radio bearer configuration parameters may comprise atleast one of signaling bearer configuration parameters, data radiobearer configuration parameters and/or security configurationparameters. The security configuration parameters may comprise securityalgorithm configuration parameters and key to use indication indicatingwhether the radio bearer configuration parameters are using master keyor secondary key. The signaling radio bearer configuration parametersmay comprise one or more signaling radio bearer configurationparameters. Each signaling radio configuration parameters may compriseat least one of srb identity, PDCP configuration parameters,reestablishPDCP indication and/or discard PDCP indication. The dataradio bearer configuration parameters may comprise one or more dataradio bearer configuration parameters. Each data radio configurationparameters may comprise at least one of drb identity, PDCP configurationparameters, SDAP configuration parameters, reestablishPDCP indicationand/or recover PDCP indication. The radio bearer configuration in theRRC setup message may comprise signaling radio configuration parametersfor SIB1. Based on the RRC setup message, the UE-RRC layer may establishSRB1. Based on the RRC setup message, the UE-RRC layer may perform acell group configuration or radio bearer configuration. The UE-RRC layermay stop a barring timer and wait timer for the cell sending the RRCsetup message. Based on receiving the RRC setup message, the UE-RRClayer may perform one or more of the following:

-   -   transitioning to RRC connected state;    -   stopping a cell re-selection procedure;    -   considering the current cell sending the RRC setup message to be        the PCell; or/and    -   sending an RRC setup complete message by setting the content of        the RRC setup complete message.

A UE-RRC layer may receive an RRC resume message in response to an RRCresume request message. Based on the RRC resume message, the UE-RRClayer may discard a UE inactive AS context and release a suspendconfiguration parameters except ran notification area information. Basedon the configuration parameters in the RRC resume message, the UE-RRClayer may perform a cell group configuration, a radio bearerconfiguration, security key update procedure, measurement configurationprocedure. Based on receiving the RRC resume message, the UE-RRC layermay perform one or more of the following:

-   -   indicating upper layers (e.g., NAS layer) that the suspended RRC        connection has been resumed;    -   resuming SRB2, all DRBs and measurements;    -   entering RRC connected state;    -   stopping a cell re-selection procedure;    -   considering the current cell sending the RRC resume message to        be the PCell; or/and    -   sending an RRC resume complete message by setting the content of        the RRC resume complete message.

A UE-RRC layer may receive an RRC reject message in response to an RRCsetup request message or an RRC resume request message. The RRC rejectmessage may contain wait timer. Based on the wait timer, the UE-RRClayer may start timer T302, with the timer value set to the wait timer.Based on the RRC reject message, the UE-RRC layer may inform upperlayers (e.g., UE-NAS layer) about the failure to setup an RRC connectionor resume an RRC connection. The UE-RRC layer may reset MAC and releasethe default MAC cell group configuration. Based on the RRC Rejectreceived in response to a request from upper layers, the UE-RRC layermay inform the upper layer (e.g., NAS layer) that access barring isapplicable for all access categories except categories ‘0’ and ‘2’.

A UE-RRC layer may receive an RRC reject message in response to an RRCresume request message. Based on the RRC reject message, The UE-RRClayer may discard current security keys. The UE-RRC layer may suspendSRB1. The UE-RRC layer may set pending rna update value to true ifresume is triggered due to an RNA update.

A UE-RRC layer may perform a cell (re)selection procedure whileperforming an RRC procedure to establish an RRC connection. Based oncell selection or cell reselection, the UE-RRC layer may change a cellon the UE camped and stop the RRC procedure. The UE-RRC layer may informupper layers (e.g., NAS layer) about the failure of the RRC procedure.

A UE may fail in a random access procedure to establish connection witha base station. A UE may store connection establishment failureinformation. The connection establishment failure information maycomprise at least one of: a failed cell identity which is the globalcell identity of a cell where connection establishment failure isdetected; location information of the UE comprising coordinates of thelocation and/or the horizontal velocity of the UE; measurement resultsof the failed cell comprising RSRP and RSRQ, if available, of the cellwhere connection establishment failure is detected and based onmeasurements collected up to the moment the UE detected the failure;measurements of neighbour cells; time since failure indicating the timethat elapsed since the last connection establishment failure; a numberof preambles sent indicating the number of preambles sent by MAC for thefailed random access procedure; contention detected indicating whethercontention resolution was not successful for at least one of thetransmitted preambles for the failed random access procedure; or maximumtransmission power reached indicating whether or not the maximum powerlevel was used for the last transmitted preamble. The UE may send areport comprising the connection establishment failure information(e.g., a connection establishment failure report) to a base station.

A UE may fail in a RACH procedure. The UE may store the RACH failureinformation. The RACH failure information may comprise at least one of anumber of preambles sent indicating the number of preambles sent by MACfor the failed random access procedure or contention detected indicatingwhether contention resolution was not successful for at least one of thetransmitted preambles for the failed random access procedure. The UE maysend a report comprising the rach failure information (e.g., a rachreport) to a base station.

Based on receiving an RRC reconfiguration message from a base station, aUE-RRC layer may perform reconfiguration with sync in at least one ofthe following cases: (1) reconfiguration with sync and security keyrefresh, involving random access (RA) to the PCell/PSCell, MAC reset,refresh of security and re-establishment of RLC and PDCP triggered byexplicit layer 2 (L2) indicators; or (2) reconfiguration with sync butwithout security key refresh, involving RA to the PCell/PSCell, MACreset and RLC re-establishment and PDCP data recovery (for AM DRB)triggered by explicit L2 indicators.

A UE-RRC layer may receive an RRC reconfiguration message withreconfiguration sync information element (IE) or mobility controlinformation from a base station. Based on the RRC reconfigurationmessage, the UE may perform a random access procedure to a base stationindicated in the reconfiguration sync IE or mobility control informationin the RRC reconfiguration message. Based on the random access procedurebeing successfully completed, the UE may send an RRC reconfigurationcomplete message to the base station. The UE and the base station mayconsider sending/receiving the RRC reconfiguration complete messagesuccessfully as reconfiguration with sync completion. Thereconfiguration with sync completion may include at least one ofhandover completion or PSCell addition for cell group addition.

For normal service, a UE may camp on a suitable cell, monitor controlchannel(s) of the camped on cell. From the camped on cell, the UE mayreceive system information (SI) from the PLMN. The UE may receiveregistration area information from the PLMN (e.g., tacking area code(TAC)) and receive other AS and NAS Information from the SI. The UE mayreceive paging and notification messages from the PLMN and initiatetransfer to connected mode if the UE is registered in the PLMN. The UEmay regularly search for a better cell according to the cell reselectioncriteria. If a better cell is found, that cell is selected. The UE maycamped on the selected cell.

A base station may provide priorities of different frequencies (e.g.,cell reselection priorities) on same RAT or inter-RAT frequencies to aUE in system information, in dedicated signaling (e.g., an RRC releasemessage), or by inheriting from another RAT at inter RAT cell(re)selection. The UE may store the priorities of frequencies providedby the dedicated signaling.

A base station may provide redirection carrier information. Theredirection carrier information may comprise at least one of one or morefrequencies or one or more core network types. An RRC release messagecomprise the redirection carrier information. The base station mayprovide the RRC release message to transition a UE to RRC inactive orRRC inactive state. Based on the RRC release message, the UE may performcell selection procedure. Based on the redirection carrier information,the UE may perform a cell selection procedure to find a suitable cell ifthe RRC release message contains the redirection carrier information.Otherwise, the UE may perform the cell selection procedure on a carrierof RAT which the UE selects currently (e.g., NR carrier or LTE carrier).

A UE in RRC idle or RRC inactive state may perform one of two proceduressuch as initial cell selection and cell selection by leveraging storedinformation. The UE may perform the initial cell selection when the UEdoesn't have stored cell information for the selected PLMN. Otherwise,the UE may perform the cell selection by leveraging stored information.For initial cell selection, a UE may scan all RF channels in the NRbands according to its capabilities to find a suitable cell. Based onresults of the scan, the UE may search for the strongest cell on eachfrequency. The UE may select a cell which is a suitable cell. For thecell selection by leveraging stored information, the UE may requiresstored information of frequencies and optionally also information oncell parameters from previously received measurement control informationelements or from previously detected cells. Based on the storedinformation, the UE may search a suitable cell and select the suitablecell if the UE found the suitable cell. If the UE does not found thesuitable cell, the UE may perform the initial cell selection.

A base station may configure cell selection criteria for cell selection.a UE may seek to identify a suitable cell for the cell selection. Thesuitable cell is one for which satisfies following conditions: (1) themeasured cell attributes satisfy the cell selection criteria, (2) thecell PLMN is the selected PLMN, registered or an equivalent PLMN, (3)the cell is not barred or reserved, and (4) the cell is not part oftracking area which is in the list of “forbidden tracking areas forroaming”. An RRC layer in a UE may inform a NAS layer in the UE of cellselection and reselection result based on changes in received systeminformation relevant for NAS. For example, the cell selection andreselection result may be a cell identity, tracking area code and a PLMNidentity.

A UE may detect a failure of a connection with a base station. Thefailure comprises at least one of:

-   -   a radio link failure;    -   a reconfiguration with sync failure;    -   a mobility failure from new radio (NR);    -   an integrity check failure indication from lower layers (e.g.,        PDCP layer) concerning signaling radio bearer 1 (SRB1) or        signaling radio bearer 2 (SRB2); or an RRC connection        reconfiguration failure.

The radio link failure may be a radio link failure of a primary cell ofthe base station. The base station may send a reconfiguration with syncin an RRC message to the UE in RRC connected state. The reconfigurationwith sync may comprise a reconfiguration timer (e.g., T304). Based onreceiving the reconfiguration sync, the UE may start the reconfigurationtimer and perform the reconfiguration with sync (e.g., handover). Basedon expiry of the reconfiguration timer, the UE determine thereconfiguration sync failure. A base station may send mobility from NRcommand message to the UE in RRC connected state. Based on receiving themobility from NR command message, the UE may perform to handover from NRto a cell using other RAT (e.g., E-UTRA). The UE may determine themobility failure from NR based on at least one of conditions being met:

if the UE does not succeed in establishing the connection to the targetradio access technology; or if the UE is unable to comply with any partof the configuration included in the mobility from NR command message;or if there is a protocol error in the inter RAT information included inthe mobility from NR message.

Based on detecting the failure, the UE may initiate an RRC connectionreestablishment procedure. Based on initiating the RRC connectionreestablishment procedure, the UE may start a timer T311, suspend allradio bearers except for SRB0, reset MAC (layer). Based on initiatingthe RRC connection reestablishment procedure, the UE may release MCGSCells, release special cell (SpCell) configuration parameters andmulti-radio dual connectivity (MR-DC) related configuration parameters.For example, based on initiating the RRC connection reestablishmentprocedure, the UE may release master cell group configurationparameters.

Cell group configuration parameters may be used to configure a mastercell group (MCG) or secondary cell group (SCG). If the cell groupconfiguration parameters are used to configure the MCG, the cell groupconfiguration parameters are master cell group configuration parameters.If the cell group configuration parameters are used to configure theSCG, the cell group configuration parameters are secondary cell groupconfiguration parameters. A cell group comprises of one MAC entity, aset of logical channels with associated RLC entities and of a primarycell (SpCell) and one or more secondary cells (SCells). The cell groupconfiguration parameters (e.g., master cell group configurationparameters or secondary cell group configuration parameters) maycomprise at least one of RLC bearer configuration parameters for thecell group, MAC cell group configuration parameters for the cell group,physical cell group configuration parameters for the cell group, SpCellconfiguration parameters for the cell group or SCell configurationparameters for the cell group. The MAC cell group configurationparameters may comprise MAC parameters for a cell group wherein the MACparameters may comprise at least DRX parameters. The physical cell groupconfiguration parameters may comprise cell group specific L1 (layer 1)parameters.

The special cell (SpCell) may comprise a primary cell (PCell) of an MCGor a primary SCG cell (PSCell) of a SCG. The SpCell configurationparameters may comprise serving cell specific MAC and PHY parameters fora SpCell. The MR-DC configuration parameters may comprise at least oneof SRB3 configuration parameters, measurement configuration parameterfor SCG, SCG configuration parameters.

Based on initiating the RRC connection reestablishment procedure, the UEmay perform a cell selection procedure. Based on the cell selectionprocedure, the UE may select a cell based on a signal quality of thecell exceeding a threshold. The UE may select a cell based on a signalquality of the cell exceeding a threshold. The UE may determine, basedon a cell selection procedure, the selected cell exceeding thethreshold. The signal quality comprises at least one of:

-   -   a reference signal received power;    -   a received signal strength indicator;    -   a reference signal received quality; or    -   a signal to interference plus noise ratio.

Based on selecting a suitable cell, the UE may stop the timer 311 andstart a timer T301. Based on selecting the suitable cell, the UE maystop a barring timer T390 for all access categories. Based on stoppingthe barring timer T390, the UE may consider a barring for all accesscategory to be alleviated for the cell. Based on selecting the cell, theUE may apply the default L1 parameter values except for the parametersprovided in SIB1, apply the default MAC cell group configuration, applythe CCCH configuration, apply a timer alignment timer in SIB1 andinitiate transmission of the RRC reestablishment request message.

The UE may stop the timer T301 based on reception of an RRC responsemessage in response of the RRC reestablishment request message. The RRCresponse message may comprise at least one of RRC reestablishmentmessage or RRC setup message or RRC reestablishment reject message. TheUE may stop the timer T301 when the selected cell becomes unsuitable.

Based on the cell selection procedure triggered by initiating the RRCconnection reestablishment procedure, the UE may select an inter-RATcell. Based on selecting an inter-RAT cell, the UE (UE-AS layer) may goto RRC IDLE state and may provide a release cause ‘RRC connectionfailure’ to upper layers (UE-NAS layer) of the UE.

Based on initiating the transmission of the RRC reestablishment requestmessage, the UE may send the RRC reestablishment message. The RRCreestablishment message may comprise at least one of C-RNTI used in thesource PCell, a physical cell identity (PCI) of the source PCell, shortMAC-I or a reestablishment cause. The reestablishment cause may compriseat least one of reconfiguration failure, handover failure or otherfailure.

Based on initiating the transmission of the RRC reestablishment requestmessage, the UE (RRC layer) may re-establish PDCP for SRB1, re-establishRLC for SRB1, apply default SRB configurations for SRB1, configure lowerlayers (PDCP layer) to suspend integrity protection and ciphering forSRB1, resume SRB1 and submit the RRC reestablishment request message tolower layers (PDCP layer) for transmission. Based on submitting the RRCreestablishment request message to lower layers, the UE may send the RRCreestablishment request message to a target base station via the cellselected based on the cell selection procedure wherein the target basestation may or may not be the source base station.

Based on expiry of the timer T311 or T301, the UE (UE-AS layer) may goto RRC IDLE state and may provide a release cause ‘RRC connectionfailure’ to upper layers (UE-NAS layer) of the UE.

Based on receiving the release cause ‘RRC connection failure’, the UE(UE-NAS layer) may perform a NAS signaling connection recovery procedurewhen the UE does not have signaling pending and user data pending. Basedon performing the NAS signaling connection recovery procedure, the UEmay initiate the registration procedure by sending a Registrationrequest message to the AMF.

Based on receiving the release cause ‘RRC connection failure’, the UE(UE-NAS layer) may perform a service request procedure by sending aservice request message to the AMF when the UE has signaling pending oruser data pending.

Based on receiving the RRC reestablishment request message, the targetbase station may check whether the UE context of the UE is locallyavailable. Based on the UE context being not locally available, thetarget base station may perform a retrieve UE context procedure bysending a retrieve UE context request message to the source base station(the last serving base station) of the UE.

For RRC connection reestablishment procedure, the retrieve UE contextrequest message may comprise at least one of a UE context ID, integrityprotection parameters or a new cell identifier. The UE context ID maycomprise at least one of C-RNTI contained the RRC reestablishmentrequest message, a PCI of the source PCell (the last serving PCell). Theintegrity protection parameters for the RRC reestablishment may be theshort MAC-I. The new cell identifier may be an identifier of the targetcell wherein the target cell is a cell where the RRC connection has beenrequested to be re-established.

For the RRC connection reestablishment procedure, based on receiving theretrieve UE context request message, the source base station may checkthe retrieve UE context request message. If the source base station isable to identify the UE context by means of the UE context ID, and tosuccessfully verify the UE by means of the integrity protectioncontained in the retrieve UE context request message, and decides toprovide the UE context to the target base station, the source basestation may respond to the target base station with a retrieve UEcontext response message. If the source base station is not able toidentify the UE context by means of the UE context ID, or if theintegrity protection contained in the retrieve UE context requestmessage is not valid, the source base station may respond to the targetbase station with a retrieve UE context failure message.

For the RRC connection reestablishment procedure, the retrieve UEcontext response message may comprise at least one of Xn applicationprotocol (XnAP) ID of the target base station, XnAP ID of the sourcebase station, globally unique AMF identifier (GUAMI) or UE contextinformation (e.g., UE context information retrieve UE context response).The UE context information may comprise at least one of a NG-C UEassociated signaling reference, UE security capabilities, AS securityinformation, UE aggregate maximum bit rate, PDU session to be setuplist, RRC context, mobility restriction list or index to RAT/frequencyselection priority. The NG-C UE associated signaling reference may be aNG application protocol ID allocated at the AMF of the UE on the NG-Cconnection with the source base station. The AS security information maycomprise a security key of a base station (K_(gNB)) and next hopchaining count (NCC) value. The PDU session to be setup list maycomprise PDU session resource related information used at UE context inthe source base station. The PDU session resource related informationmay comprise a PDU session ID, a PDU session resource aggregate maximumbitrate, a security indication, a PDU session type or QoS flows to besetup list. The security indication may comprise a user plane integrityprotection indication and confidentiality protection indication whichindicates the requirements on user plane (UP) integrity protection andciphering for the corresponding PDU session, respectively. The securityindication may also comprise at least one of an indication whether UPintegrity protection is applied for the PDU session, an indicationwhether UP ciphering is applied for the PDU session and the maximumintegrity protected data rate values (uplink and downlink) per UE forintegrity protected DRBs. The PDU session type may indicate at least oneof internet protocol version 4 (IPv4), IPv6, IPv4v6, ethernet orunstructured. The QoS flow to be setup list may comprise at least one ofQoS flow identifier, QoS flow level QoS parameters (the QoS Parametersto be applied to a QoS flow) or bearer identity.

For the RRC connection reestablishment procedure, the retrieve UEcontext failure message may comprise at least XnAP ID of the target basestation and a cause value.

For the RRC connection reestablishment procedure, based on receiving theretrieve UE context response message, the target base station may sendan RRC reestablishment message to the UE. The RRC reestablishmentmessage may comprise at least a network hop chaining count (NCC) value.

Based on receiving the RRC reestablishment message, the UE may derive anew security key of a base station (K_(gNB)) based on at least one ofcurrent K_(gNB) or next hop (NH) parameters associated to the NCC value.Based on the new security key of the base station and a previouslyconfigured integrity protection algorithm, the UE may derive a securitykey for integrity protection of an RRC signaling (K_(RRCint)) and asecurity key for integrity protection of user plane (UP) data(K_(UPint)). Based on the new security key of the base station and apreviously configured ciphering algorithm, the UE may derive a securitykey for ciphering of an RRC signaling (K_(RRCenc)) and a security keyfor ciphering of user plane (UP) data (K_(UPenc)). Based on theK_(RRCint), and the previously configured integrity protectionalgorithm, the UE may verify the integrity protection of the RRCreestablishment message. Based on the verifying being failed, the UE(UE-AS layer) may go to RRC IDLE state and may provide a release cause‘RRC connection failure’ to upper layers (UE-NAS layer) of the UE. Basedon the verifying being successful, the UE may configure to resumeintegrity protection for SRB1 based on the previously configuredintegrity protection algorithm and the K_(RRCint) and configure toresume ciphering for SRB1 based on the previously configured cipheringalgorithm and K_(RRCenc). The UE may send an RRC reestablishmentcomplete message to the target base station.

Based on receiving the retrieve UE context failure message, the targetbase station may send an RRC release message to the UE. For example,based on the retrieve UE context failure message comprising the RRCrelease message, the target base station may send the RRC releasemessage to the UE. Based on receiving the retrieve UE context failuremessage, the target base station may send an RRC setup message or an RRCreject message. Based on receiving the retrieve UE context failuremessage, the target base station may not send any response message tothe UE.

FIG. 17 illustrates an example of an RRC connection reestablishmentprocedure. The UE in an RRC connected state may send and receive datato/from a first base station (for example, a source base station) via acell 1 wherein the cell 1 is a primary cell (PCell) of the first basestation. The UE may detect a failure of a connection with the first basestation. Based on the failure, the UE may initiate the RRCreestablishment procedure. Based on initiating the RRC connectionreestablishment procedure, the UE may start a timer T311, suspend allradio bearers except for SRB0, and/or reset a MAC (layer). Based oninitiating the RRC connection reestablishment procedure, the UE mayrelease MCG SCells, release the special cell (SpCell) configurationparameters and the multi-radio dual connectivity (MR-DC) relatedconfiguration parameters. Based on initiating the RRC connectionreestablishment procedure, the UE may perform a cell selectionprocedure. Based on the cell selection procedure, the UE may select acell 2 of a second base station (for example, a target base station)wherein the cell 2 is a suitable cell. Based on selecting a suitablecell, the UE may stop the timer T311 and start a timer T301. Based onselecting the suitable cell, the UE may stop a barring timer T390 forall access categories. Based on stopping the barring timer T390, the UEmay consider a barring for all access category to be alleviated for thecell. Based on selecting the cell, the UE may apply the default L1parameter values except for the parameters provided in SIB1, apply thedefault MAC cell group configuration, apply the CCCH configuration,apply a timer alignment timer in SIB1 and initiate transmission of theRRC reestablishment request message. The RRC reestablishment message maycomprise at least one of C-RNTI used in the source PCell (e.g., the cell1), a physical cell identity (PCI) of the source PCell, short MAC-I or areestablishment cause. Based on initiating the transmission of the RRCreestablishment request message, the UE (RRC layer) may re-establishPDCP for SRB1, re-establish RLC for SRB1, apply default SRBconfigurations for SRB1, configure lower layers (PDCP layer) to suspendintegrity protection and ciphering for SRB1, resume SRB1 and submit theRRC reestablishment request message to lower layers (PDCP layer) fortransmission. Based on initiating the transmission of the RRCreestablishment request message, the UE may send the RRC reestablishmentrequest message to the second base station via the cell 2. Based onreceiving the RRC reestablishment request message, the second basestation may check whether the UE context of the UE is locally available.Based on the UE context being not locally available, the second basestation may perform the retrieve UE context procedure by sending aretrieve UE context request message to the source base station of theUE. The retrieve UE context request message may comprise at least one ofC-RNTI, a PCI of the source PCell (the last serving PCell) or shortMAC-I. Based on receiving the retrieve UE context request message, thesource base station may check the retrieve UE context request message.If the source base station is able to identify the UE context by meansof the C-RNTI, and to successfully verify the UE by means of the shortMAC-I, and decides to provide the UE context to the second base station,the source base station may respond to the second base station with aretrieve UE context response message. The retrieve UE context responsemessage may comprise at least of GUAMI or the UE context information.Based on receiving the retrieve UE context response message, the secondbase station may send an RRC reestablishment message to the UE. The RRCreestablishment message may comprise a network hop chaining count (NCC)value. Based on receiving the RRC reestablishment message, the UE mayderive a new security key of a base station (K_(gNB)) based on at leastone of current K_(gNB) or next hop (NH) parameters associated to the NCCvalue. Based on the new security key of a base station (K_(gNB)) and thepreviously configured security algorithms, the UE may derive securitykeys for integrity protection and ciphering of RRC signaling (e.g.,K_(RRCint) and K_(RRCenc) respectively) and user plane (UP) data (e.g.,K_(UPint) and K_(UPenc) respectively). Based on the security key forintegrity protection of the RRC signaling (K_(RRCint)), the UE mayverify the integrity protection of the RRC reestablishment message.Based on the verifying being successful, the UE may configure to resumeintegrity protection for SRB1 based on the previously configuredintegrity protection algorithm and the K_(RRCint) and configure toresume ciphering for SRB1 based on the previously configured cipheringalgorithm and the K_(RRCenc). The second base station may send a firstRRC reconfiguration message. The RRC first reconfiguration message maycomprise the SpCell configuration parameters. Based on receiving theSpCell configuration parameters, the UE may initiate transmission andreception of data to/from the second base station. The UE may send anRRC reestablishment complete message to the second base station. The RRCreestablishment complete message may comprise measurement report. Basedon receiving the measurement report, the second base station maydetermine to configure SCells and/or secondary cell groups (e.g., SCG orPSCells). Based on the determining, the second base station may send asecond RRC reconfiguration message comprising SCells configurationparameters and/or MR-DC related configuration parameters. Basedreceiving the second RRC reconfiguration message, the UE may transmitand receive data via the SCells and/or SCGs.

The RRC reconfiguration message may comprise at least one of cell groupconfiguration parameters of MCG and/or SCG, radio bearer configurationparameters or AS security key parameters.

A UE may remain in CM-CONNECTED and move within an area configured bythe base station without notifying the base station when the UE is inRRC inactive state where the area is an RNA. In RRC inactive state, alast serving base station may keep the UE context and the UE-associatedNG connection with the serving AMF and UPF. Based on received downlinkdata from the UPF or downlink UE-associated signaling from the AMF whilethe UE is in RRC inactive state, the last serving base station may pagein the cells corresponding to the RNA and may send RAN Paging via an Xninterface to neighbor base station(s) if the RNA includes cells ofneighbor base station(s).

An AMF may provide to the base station a core network assistanceinformation to assist the base station's decision whether a UE can besent to RRC inactive state. The core network assistance information mayinclude the registration area configured for the UE, the periodicregistration update timer, a UE identity index value, the UE specificDRX, an indication if the UE is configured with mobile initiatedconnection only (MICO) mode by the AMF, or the expected UE behavior. Thebase station may use the UE specific DRX and the UE identity index valueto determine a paging occasion for RAN paging. The base station may useperiodic registration update timer to configure periodic RNA updatetimer (e.g., a timer T380). The base station may use an expected UEbehavior to assist the UE RRC state transition decision.

A base station may initiate an RRC connection release procedure totransit an RRC state of a UE from RRC connected state to RRC idle state,from an RRC connected state to RRC inactive state, from RRC inactivestate back to RRC inactive state when the UE tries to resume, or fromRRC inactive state to RRC idle state when the UE tries to resume. TheRRC connection procedure may also be used to release an RRC connectionof the UE and redirect a UE to another frequency. The base station maysend the RRC release message comprising suspend configuration parameterswhen transitioning RRC state of the UE to RRC inactive state. Thesuspend configuration parameters may comprise at least one of a resumeidentity, RNA configuration, RAN paging cycle, or network hop chainingcount (NCC) value wherein the RNA configuration may comprise RNAnotification area information, or periodic RNA update timer value (e.g.,T380 value). The base station may use the resume identity (e.g.,inactive-RNTI (I-RNTI)) to identify the UE context when the UE is in RRCinactive state.

If the base station has a fresh and unused pair of {NCC, next hop (NH)},the base station may include the NCC in the suspend configurationparameters. Otherwise, the base station may include the same NCCassociated with the current K_(gNB) in the suspend configurationparameters. The NCC is used for AS security. The base station may deletethe current AS keys (e.g., K_(RRCenc), K_(UPenc)), and K_(UPint) aftersending the RRC release message comprising the suspend configurationparameters to the UE but may keep the current AS key K_(RRCint). If thesent NCC value is fresh and belongs to an unused pair of {NCC, NH}, thebase station may save the pair of {NCC, NH} in the current UE ASsecurity context and may delete the current AS key K_(gNB). If the sentNCC value is equal to the NCC value associated with the current K_(gNB),the base station may keep the current AS key K_(gNB) and NCC. The basestation may store the sent resume identity together with the current UEcontext including the remainder of the AS security context.

Upon receiving the RRC release message comprising the suspendconfiguration parameters from the base station, the UE may verify thatthe integrity of the received RRC release message comprising the suspendconfiguration parameters is correct by checking PDCP MAC-I. If thisverification is successful, then the UE may take the received NCC valueand save it as stored NCC with the current UE context. The UE may deletethe current AS keys K_(RRCenc), K_(UPenc), and K_(UPint), but keep thecurrent AS key K_(RRCint) key. If the stored NCC value is different fromthe NCC value associated with the current K_(gNB), the UE may delete thecurrent AS key K_(gNB). If the stored NCC is equal to the NCC valueassociated with the current K_(gNB), the UE shall keep the current ASkey KgNB. The UE may store the received resume identity together withthe current UE context including the remainder of the AS securitycontext, for the next state transition.

Based on receiving the RRC release message comprising the suspendconfiguration parameters, the UE may reset MAC, release the default MACcell group configuration, re-establish RLC entities for SRB1. Based onreceiving the RRC release message comprising suspend configurationparameters, the UE may store in the UE inactive AS context currentconfiguration parameters and current security keys. For example, the UEmay store some of the current configuration parameters. The storedcurrent configuration parameters may comprise a robust headercompression (ROHC) state, quality of service (QoS) flow to DRB mappingrules, the C-RNTI used in the source PCell, the cell identity and thephysical cell identity of the source PCell, and all other parametersconfigured except for the ones within reconfiguration with sync andserving cell configuration common parameters in SIB. The stored securitykeys may comprise at least one of K_(gNB) and K_(RRCint). The servingcell configuration common parameters in SIB may be used to configurecell specific parameters of a UE's serving cell in SIB1. Based onreceiving the RRC release message comprising the suspend configurationparameters, the UE may suspend all SRB(s) and DRB(s) except for SRB0.Based on receiving the RRC release message comprising suspendconfiguration parameters, the UE may start a timer T380, enter RRCinactive state, perform cell selection procedure.

The UE in RRC inactive state may initiate an RRC connection resumeprocedure. For example, based on having data or signaling to transmit,or receiving RAN paging message, the UE in RRC inactive state mayinitiate the RRC connection resume procedure. Based on initiating theRRC connection resume procedure, the UE may select access category basedon triggering condition of the RRC connection resume procedure andperform unified access control procedure based on the access category.Based on the unified access control procedure, the UE may consideraccess attempt for the RRC connection resume procedure as allowed. Basedon considering the access attempt as allowed, the UE may apply thedefault L1 parameter values as specified in corresponding physical layerspecifications, except for the parameters for which values are providedin SIB1, apply the default SRB1 configuration, apply the CCCHconfiguration, apply the time alignment timer common included in SIB1,apply the default MAC cell group configuration, start a timer T319 andinitiate transmission of an RRC resume request message.

Based on initiating the transmission of the RRC resume request message,the UE may set the contents of the RRC resume request message. The RRCresume request message may comprise at least one of resume identity,resume MAC-I or resume cause. The resume cause may comprise at least oneof emergency, high priority access, mt access, mo signalling, mo data,mo voice call, mo sms, ran update, mps priority access, mcs priorityaccess.

Based on initiating the transmission of the RRC resume request message,the UE may restore the stored configuration parameters and the storedsecurity keys from the (stored) UE inactive AS context except for themaster cell group configuration parameters, MR-DC related configurationparameters (e.g., secondary cell group configuration parameters) andPDCP configuration parameters. The configuration parameter may compriseat least one of the C-RNTI used in the source PCell, the cell identityand the physical cell identity of the source PCell, and all otherparameters configured except for the ones within reconfiguration withsync and serving cell configuration common parameters in SIB. Based oncurrent (restored) K_(gNB) or next hop (NH) parameters associated to thestored NCC value, the UE may derive a new key of a base station(K_(gNB)). Based on the new key of the base station, the UE may derivesecurity keys for integrity protection and ciphering of RRC signalling(e.g., K_(RRCenc) and K_(RRCint) respectively) and security keys forintegrity protection and ciphering of user plane data (e.g., K_(UPint)and the K_(UPenc) respectively). Based on configured algorithm and theK_(RRCint) and K_(UPint), the UE may configure lower layers (e.g., PDCPlayer) to apply integrity protection for all radio bearers except SRB0.Based on configured algorithm and the K_(RRCenc) and the K_(UPenc), theUE may configure lower layers (e.g., PDCP layer) to apply ciphering forall radio bearers except SRB0.

Based on initiating the transmission of the RRC resume request message,the UE may re-establish PDCP entities for SRB1, resume SRB1 and submitthe RRC resume request message to lower layers wherein the lower layersmay comprise at least one of PDCP layer, RLC layer, MAC layer orphysical (PHY) layer.

A target base station may receive the RRC resume request message. Basedon receiving the RRC resume request message, the target base station maycheck whether the UE context of the UE is locally available. Based onthe UE context being not locally available, the target base station mayperform the retrieve UE context procedure by sending the retrieve UEcontext request message to the source base station (the last servingbase station) of the UE. The retrieve UE context request message maycomprise at least one of a UE context ID, integrity protectionparameters, a new cell identifier or the resume cause wherein the resumecause is in the RRC resume request message.

For the RRC connection resume procedure, based on receiving the retrieveUE context request message, the source base station may check theretrieve UE context request message. If the source base station is ableto identify the UE context by means of the UE context ID, and tosuccessfully verify the UE by means of the integrity protectioncontained in the retrieve UE context request message, and decides toprovide the UE context to the target base station, the source basestation may respond to the target base station with the retrieve UEcontext response message. If the source base station is not able toidentify the UE context by means of the UE context ID, or if theintegrity protection contained in the retrieve UE context requestmessage is not valid, or, if the source base station decides not toprovide the UE context to the target base station, the source basestation may respond to the target base station with a retrieve UEcontext failure message.

For the RRC connection resume procedure, the retrieve UE context failuremessage may comprise at least XnAP ID of the target base station, an RRCrelease message or a cause value.

For the RRC connection resume procedure, based on receiving the retrieveUE context response message, the target base station may send an RRCresume message to the UE. The RRC resume message may comprise at leastone of radio bearer configuration parameters, cell group configurationparameters for MCG and/or SCG, measurement configuration parameters orsk counter wherein the sk counter is used to derive a security key ofsecondary base station based on K_(gNB).

Based on receiving the retrieve UE context failure message, the targetbase station may send an RRC release message to the UE. For example,based on the retrieve UE context failure message comprising the RRCrelease message, the target base station may send the RRC releasemessage to the UE. Based on receiving the retrieve UE context failuremessage, the target base station may send an RRC setup message or an RRCreject message. Based on receiving the retrieve UE context failuremessage, the target base station may not send any response message tothe UE.

Based on receiving the RRC resume message, the UE may stop the timerT319 and T380. Based on receiving the RRC resume message, the UE mayrestore mater cell group configuration parameters, secondary cell groupconfiguration parameters and PDCP configuration parameters in the UEinactive AS context. Based on restoring the master cell groupconfiguration parameter and/or the secondary cell group configurationparameters, the UE may configure SCells of MCG and/or SCG by configuringlower layers to consider the restored MCG and/or SCG SCells to be indeactivated state, discard the UE inactive AS context and release thesuspend configuration parameters.

Based on receiving the cell group configuration parameters in the RRCresume message, the UE may perform cell group configuration of MCGand/or SCG. Based on receiving the radio bearer configuration parametersin the RRC resume message, the UE may perform radio bearerconfiguration. Based on the sk counter in the RRC resume message, the UEmay perform to update the security key of secondary base station.

FIG. 18 illustrates an example of an RRC connection resume procedure. AUE in RRC connected state may transmit and receive data to/from a firstbase station (a source base station) via a cell 1. The first basestation may determine to transit a UE in RRC connected state to RRCinactive state. Based on the determining, the base station may send anRRC release message comprising the suspend configuration parameters.Based on receiving the RRC release message comprising suspendconfiguration parameters, the UE may store in the UE inactive AS Contextthe current security keys (e.g., K_(gNB) and K_(RRCint) keys) andcurrent configuration parameters. For example, the UE may store some ofthe current configuration parameters. The stored (current) configurationparameters may be at least one of:

-   -   robust header compression (ROHC) state;    -   QoS flow to DRB mapping rules;    -   C-RNTI used in source PCell;    -   cell identity and physical cell identity of the source PCell;        and    -   all other parameters configured except for ones within        reconfiguration with sync and serving cell configuration common        parameters in SIB.

The robust header compression (ROHC) state may comprise ROHC states forall PDCP entity (or all bearers) where each PDCP entity per bearer (oreach bearer) may have one ROHC state. The QoS flow to DRB mapping rulesmay be QoS flow to DRB mapping rules for all data radio bearer (DRB)where each DRB may have one QoS follow to DRB mapping rule. Based onreceiving the RRC release message comprising suspend configurationparameters, the UE may suspend all SRB(s) and DRB(s) except for SRB0.Based on receiving the RRC release message comprising suspendconfiguration parameters, the UE may start a timer T380, enter RRCinactive state, perform cell selection procedure. Based on the cellselection procedure, the UE may select a cell 2 of a second base station(a target base station). The UE in RRC inactive state may initiate anRRC connection resume procedure. The UE may perform the unified accesscontrol procedure. Based on the unified access control procedure, the UEmay consider access attempt for the RRC connection resume procedure asallowed. The UE may apply the default L1 parameter values as specifiedin corresponding physical layer specifications, except for theparameters for which values are provided in SIB1, apply the default SRB1configuration, apply the CCCH configuration, apply the time alignmenttimer common included in SIB1, apply the default MAC cell groupconfiguration, start a timer T319 and initiate transmission of an RRCresume request message. Based on initiating the transmission of the RRCresume request message, the UE may restore the stored configurationparameters and the stored security keys from the (stored) UE inactive AScontext. For example, the UE may restore the stored configurationparameters and the stored security keys (e.g., K_(gNB) and K_(RRCint))from the stored UE Inactive AS context except for the master cell groupconfiguration parameters, MR-DC related configuration parameters (e.g.,secondary cell group configuration parameters) and PDCP configurationparameters. Based on current (restored) K_(gNB) or next hop (NH)parameters associated to the stored NCC value, the UE may derive a newkey of a base station (K_(gNB)). Based on the new key of the basestation, the UE may derive security keys for integrity protection andciphering of RRC signalling (e.g., K_(RRCenc) and K_(RRCint)respectively) and security keys for integrity protection and cipheringof user plane data (e.g., K_(UPint) and the K_(UPenc) respectively).Based on configured algorithm and the K_(RRCint) and K_(UPint), the UE(RRC layer) may configure lower layers (e.g., PDCP layer) to applyintegrity protection for all radio bearers except SRB0. Based onconfigured algorithm and the K_(RRCenc) and the K_(UPenc), the UE mayconfigure lower layers (e.g., PDCP layer) to apply ciphering for allradio bearers except SRB0. For communication between the UE and the basestation, the integrity protection and/or the ciphering may be required.Based on the integrity protection and/or the ciphering, the UE may beable to transmit and receive data to/from the second base station. TheUE may use the restored configuration parameters to transmit and receivethe data to/from the second base station. Based on initiating thetransmission of the RRC resume request message, the UE may re-establishPDCP entities for SRB1, resume SRB1 and submit the RRC resume requestmessage to lower layers. Based on receiving the RRC resume requestmessage, the second base station may check whether the UE context of theUE is locally available. Based on the UE context being not locallyavailable, the second base station may perform the retrieve UE contextprocedure by sending the retrieve UE context request message to thefirst base station (the last serving base station) of the UE. Theretrieve UE context request message may comprise at least one of resumeidentity, resume MAC-I, or the resume cause. based on receiving theretrieve UE context request message, the first base station may checkthe retrieve UE context request message. If the first base station isable to identify the UE context by means of the UE context ID, and tosuccessfully verify the UE by means of the resume MAC-I and decides toprovide the UE context to the second base station, the first basestation may respond to the second base station with the retrieve UEcontext response message. Based on receiving the retrieve UE contextresponse message, the second base station may send an RRC resume messageto the UE. Based on receiving the RRC resume message, the UE may restoremater cell group configuration parameters, secondary cell groupconfiguration parameters and PDCP configuration parameters in the UEinactive AS context. Based on restoring the master cell groupconfiguration parameter and/or the secondary cell group configurationparameters, the UE may configure SCells of MCG and/or SCG by configuringlower layers to consider the restored MCG and/or SCG SCells to be indeactivated state, discard the UE inactive AS context and release thesuspend configuration parameters. The UE may transmit and receive datavia the SCells and/or SCGs.

The RRC resume message may comprise at least one of cell groupconfiguration parameters of MCG and/or SCG, radio bearer configurationparameters or AS security key parameters (e.g., sk counter).

A base station may send an RRC release message to a UE to release an RRCconnection of the UE. Based on the RRC release message, the UE mayrelease established radio bearers as well as all radio resources.

A base station may send an RRC release message to a UE to suspend theRRC connection. Based on the RRC release message, the UE may suspend allradio bearers except for signaling radio bearer 0 (SRB0). The RRCrelease message may comprise suspend configuration parameters. Thesuspend configuration parameters may comprise next hop chaining count(NCC) and resume identity (e.g. ID or identifier).

The base station may send an RRC release message to transit a UE in anRRC connected state to an RRC idle state; or to transit a UE in an RRCconnected state to an RRC inactive state; or to transit a UE in an RRCinactive state back to an RRC inactive state when the UE tries toresume; or to transit a UE in an RRC inactive state to an RRC idle statewhen the UE tries to resume.

The base station may send an RRC release message to redirect a UE toanother frequency.

A UE may receive an RRC release message from the base station of servingcell (or PCell). Based on the RRC release message, the UE may performsUE actions for the RRC release message from the base station. The UE maydelay the UE actions for the RRC release message a period of time (e.g.,60 ms) from the moment the RRC release message was received or when thereceipt of the RRC release message was successfully acknowledged. The UEmay send HARQ acknowledgments to the base station for acknowledgments ofthe RRC release message. Based on a RLC protocol data unit (PDU)comprising the RRC release message and the RLC PDU comprising poll bit,the UE may send a RLC message (e.g. a status report) to the base stationfor acknowledgments of the RRC release message.

The UE actions for the RRC release message from the base station maycomprise at least one of:

-   -   suspending RRC connection;    -   releasing RRC connection;    -   cell (re)selection procedure; and/or    -   idle/inactive measurements.

The RRC release message from the base station may comprise the suspendconfiguration parameters. Based on the suspend configuration parameters,the UE may perform the suspending RRC connection. The suspending RRCconnection may comprise at least one of:

-   -   medium access control (MAC) reset (or resetting MAC);    -   releasing default MAC cell group configuration;    -   re-establishing RLC entities for signaling radio bearers 1        (SRB1);    -   storing current configuration parameters and current security        keys;    -   suspending bearers where the bearers comprises signaling radio        bearer and data radio bearer; and/or    -   transitioning an RRC idle state or an RRC inactive state.

For example, the suspend configuration parameters may further compriseRNA configuration parameters. Based on the RNA configuration parameters,the UE may transition to an RRC inactive state. For example, based onthe suspend configuration parameters not comprising the RNAconfiguration parameters, the UE may transition to an RRC idle state.For example, the RRC release message comprising the suspendconfiguration parameters may comprise a indication transitioning to anRRC inactive state. Based on the indication, the UE may transition to anRRC inactive state. For example, based on the RRC release message notcomprising the indication, the UE may transition to an RRC idle state.

Based on the MAC reset, the UE may perform to at least one of:

-   -   stop all timers running in the UE-MAC layer;    -   consider all time alignment timers as expired;    -   set new data indicators (NDIs) for all uplink HARQ processes to        the value 0;    -   stop, ongoing RACH procedure;    -   discard explicitly signaled contention-free Random Access        Resources, if any;    -   flush Msg 3 buffer;    -   cancel, triggered scheduling request procedure;    -   cancel, triggered buffer status reporting procedure;    -   cancel, triggered power headroom reporting procedure;    -   flush the soft buffers for all DL HARQ processes;    -   for each DL HARQ process, consider the next received        transmission for a TB as the very first transmission; and/or    -   release, temporary C-RNTI.

Based on the considering the time alignment timers as expired, the UEmay perform at least one of:

-   -   flush all HARQ buffers for all serving cells;    -   notify RRC to release PUCCH for all Serving Cells, if        configured;    -   notify RRC to release SRS for all Serving Cells, if configured;    -   clear any configured downlink assignments and configured uplink        grants;    -   clear any PUSCH resource for semi-persistent CSI reporting;        and/or    -   consider all running time alignment timers as expired.

The default MAC cell group configuration parameters may comprise bufferstatus report (BSR) configuration parameters (e.g., BSR timers) for acell group of the base station and power headroom reporting (PHR)configuration parameters (e.g., PHR timers or PHR transmission powerfactor change parameter) for the cell group of the base station.

The re-establishing RLC entities may comprise at least one of:

-   -   discarding all RLC SDUs, RLC SDU segments, and RLC PDUs, if any;    -   stopping and resetting all timers of the RLC entities;    -   resetting all state variables of the RLC entities to their        initial values.

The RRC release message from the base station may not comprise thesuspend configuration parameters. Based on the RRC message notcomprising the suspend configuration parameters, the UE may perform thereleasing RRC connection. The releasing RRC connection may comprise atleast one of:

-   -   MAC reset (or resetting MAC);    -   Discarding the stored configuration parameters and stored        security keys (or discarding the stored UE inactive AS context);    -   Releasing the suspend configuration parameters;    -   releasing all radio resources, including release of RLC entity,        MAC configuration and associated PDCP entity and SDAP for all        established radio bearers; and/or    -   transitioning to an RRC idle state.

The RRC release message may comprise cell (re)selection information. Thecell (re)selection information may comprise at least one of redirectedcarrier information or cell reselection priorities. Based on the cell(re)selection information, the UE may perform cell (re)selectionprocedure. For example, the RRC release message may comprise redirectedcarrier information. Based on the redirected carrier information, the UEmay perform the cell selection procedure. Based on the cell selectionprocedure using the redirected carrier information, the UE may changeserving cell. For example, the RRC release message may comprise cellreselection priorities. The base station may broadcast the cellreselection priorities via serving cell of the UE where the serving cellis a cell of the base station. Based on the cell reselection priorities,the UE may perform cell re-selection procedure. Based on the cellre-selection procedure using the cell reselection priorities, the UE maychange the serving cell. The base station may broadcast the cell(re)selection information (e.g., cell reselection priorities) via systeminformation. Based on the cell (re)selection information, the UE maycell (re)selection procedure in response to transitioning to an RRC idlestate or an RRC inactive state based on the RRC release message.

The RRC release message may comprise idle measurement configurationparameters or inactive measurement configuration parameters. Based onthe idle measurement configuration parameters, the UE may perform idlemeasurement. Based on the inactive measurement configuration parameters,the UE may perform inactive measurement.

The RRC release message may be RRC early data complete message.

FIG. 19 illustrates an example of UE actions for RRC release message. AUE may receive an RRC release message. Based on the RRC messagecomprising suspend configuration parameters, the UE may perform thesuspending RRC connection. Based on the RRC message not comprisingsuspend configuration parameters, the UE may perform releasing RRCconnection. Based on the RRC release message, the UE may perform cell(re)selection based on the cell (re)selection information. Based on theRRC release message comprising idle/inactive measurement configuration,the UE may perform idle/inactive measurement.

A UE may send or receive a small amount of data without transitioningfrom an RRC idle state or an RRC inactive state to an RRC connectedstate based on performing small data transmission. The performing smalldata transmission may comprise, while staying in the RRC idle state orthe RRC inactive state (e.g., without transitioning to an RRC connectedstate), at least one of:

-   -   initiating small data transmission;    -   sending small data; and/or    -   receiving a response message;

For example, based on the small data transmission, the UE in an RRC idlestate or an RRC inactive state may perform initiating small datatransmission. In response to the initiating small data transmission, theUE in an RRC idle state or an RRC inactive state may perform sendingsmall data. In response to the sending small data, the UE may receive aresponse message. For example, the response message may comprise adownlink data (or a downlink signaling). For example, based on the smalldata transmission, the UE in an RRC idle state or an RRC inactive statemay perform sending small data. In response to the sending small data,the UE in an RRC idle state or an RRC inactive state may receive aresponse message.

The sending small data may comprise at least one of sending at least oneof an RRC request message, uplink data (or uplink signaling) or bufferstatus report (BSR). For example, the sending small data may comprisesending the RRC request message. For example, the sending small data maycomprise sending the RRC request message and uplink data. For example,the sending small data may comprise sending the RRC request message, afirst uplink data and the BSR requesting uplink resource for a seconduplink data. The RRC request message may comprise at least one of:

-   -   an RRC resume request message; or    -   an RRC early data request message.

The response message may comprise at least one of:

-   -   an RRC response message in response to the RRC request message;    -   downlink data; or    -   acknowledgment for uplink data (e.g., the first uplink data); or    -   uplink resource for uplink data (e.g., the second uplink data).

The RRC response message for the RRC request message may comprise atleast one of:

-   -   an RRC release message;    -   an RRC early data complete message;    -   an RRC setup message;    -   an RRC resume message; or    -   an RRC reject message.

Based on receiving the RRC release message, the UE in an RRC idle stateor an RRC inactive state may transition to the RRC idle state or the RRCinactive state or stay in the RRC idle state or the RRC inactive state.Based receiving the RRC early data complete message, the UE in an RRCidle state or an RRC inactive state may transition to the RRC idle state(or stay in the RRC idle state). Based on receiving the RRC releasemessage or the RRC early data complete message, the UE may considersending small data being successful. Based on receiving the RRC setupmessage or the RRC resume message, the UE in an RRC idle state or an RRCinactive state may transition to an RRC connected state. Based onreceiving the RRC setup message or the RRC resume message, the UE mayconsider sending small data being successful. Based on receiving the RRCreject message, the UE in an RRC idle state or an RRC inactive state maytransition to an RRC idle state. Based on receiving the RRC rejectmessage, the UE may consider sending small data being not successful.

For example, based on the small data transmission, the UE in an RRC idlestate or an RRC inactive state may send uplink data via the Msg 3. TheMsg 3 may be a message transmitted on UL-SCH containing C-RNTI MAC CE orCCCH SDU optionally multiplexed with DTCH. For example, the CCCH SDU maybe associated with the UE contention resolution identity, as part of arandom access procedure. For example, the UE in an RRC idle state or anRRC inactive state may send the CCCH SDU using preconfigured uplinkresource (PUR). The CCCH SDU may comprise at least one of the RRCrequest message and the uplink data (e.g., the first uplink data). TheDTCH may comprise the uplink data (e.g., the first uplink data). Basedon the small data transmission, the UE in an RRC idle state or an RRCinactive state may receive downlink data in response to the sendingsmall data without transitioning to an RRC connected state. For example,based on the small data transmission, the UE in an RRC idle state or anRRC inactive state may send the RRC request message and receive at leastone of the RRC response message and/or downlink data in response to theRRC request message.

The small data transmission may comprise user plane (UP) small datatransmission and control plane (CP) small data transmission. Based onthe UP small data transmission, the UE in an RRC idle state or an RRCinactive may send uplink data via user plane (e.g., DTCH). Based on theCP small data transmission, the UE in an RRC idle state or an RRCinactive may send uplink data via control plane (e.g., CCCH). Based onthe UP small data transmission, the base station of the UE may receivedownlink data via user plane from UPF of the UE. Based on the CP smalldata transmission, the base station of the UE may receive downlink datavia control plane from AMF of the UE. In response to the CCCH SDU and/orthe DTCH SDU, the base station may send a response message to the UE inan RRC idle state or an RRC inactive.

The initiating small data transmission may comprise initiating UP smalldata transmission. The sending small data may comprise at least one ofsending UP small data and/or sending CP small data via control plane.The response message may be a response message in response to at leastone of the RRC request message and/or the (first) uplink data.

For the UP small data transmission, the DTCH SDU may comprise the uplinkdata.

For example, for the UP small data transmission, the UE may send theDTCH SDU multiplexed with CCCH SDU. For example, for the UP small datatransmission, the CCCH SDU may comprise at least one of the uplink dataand an RRC request message. For example, for the UP small datatransmission, the RRC request message may an RRC resume request message.For the CP small data transmission, the UE may send CCCH SDU comprisingthe uplink data. For example, for the CP small data transmission, theRRC request message comprise the uplink data. For example, for the CPsmall data transmission, the RRC request message may be an RRC earlydata request message.

FIG. 20 illustrates an example of UP small data transmission. A UE in anRRC connected state may communicate with a first base station based onfirst configuration parameters and first security keys. For example, thefirst base station may send the first configuration parameters andsecurity parameters (e.g., sk counter, security algorithms or NCC value)to the UE. Based on the security parameters, the UE may derive a firstsecurity keys. The UE may configure the first configuration parametersand the first security keys. Based on the first configuration parametersand the first security keys, the UE may communication with the firstbase station (e.g., send uplink data to the first base station andreceive downlink data from the first base station). The first basestation may send an RRC release message comprising first suspendconfiguration parameters where the first suspend configurationparameters comprises a first NCC value and a first resume identity (ID).In response of receiving the RRC release message, the UE may perform thesuspending RRC connection based on the first suspend configurationparameters.

For example, the suspending RRC connection based on the first suspendconfiguration parameters may comprise that the UE performs at least oneof:

-   -   discarding uplink data in uplink buffer;    -   storing the first configuration parameters and the first        security keys;    -   suspending bearers except for SRB0; and/or    -   transitioning to an RRC idle state or an RRC inactive state.

For example, the first configuration parameters may comprise at leastone of:

-   -   robust header compression (ROHC) state;    -   QoS flow to DRB mapping rules;    -   C-RNTI used in source PCell;    -   cell identity and physical cell identity of the source PCell;        and    -   all other parameters configured except for ones within        reconfiguration with sync and serving cell configuration common        parameters in SIB.

The UE in the RRC idle state or the RRC inactive state may initiate UPsmall data transmission using the first suspend configurationparameters. For example, the UE in the RRC idle state or the RRCinactive may initiate the UP small data transmission using the firstsuspend configuration parameters based on a first uplink data or a firstsignaling being generating in uplink buffer. For example, the UE in theRRC idle state or the RRC inactive may initiate the UP small datatransmission using the first suspend configuration parameters based onreceiving paging message. Based on the initiating UP small datatransmission using the first suspend configuration parameters, the UEmay perform the initiating an RRC connection resume procedure using thefirst suspend configuration parameters and resume suspended bearers. Forexample, the initiating UP small data transmission using the firstsuspend configuration parameters may comprise that the UE perform atleast one of:

-   -   restoring the first configuration parameters and the first        security keys;    -   deriving a first resume MAC-I based on the first security keys;    -   deriving second security keys based on the first security keys        and the first NCC value; and    -   resuming all suspended bearers.

In response to the initiating UP small data transmission using the firstsuspend configuration parameters, the UE may perform sending UP smalldata using the first suspend configuration parameters. For example, thesending UP small data using the first suspend configuration parametersmay comprise the initiating transmission of an RRC resume requestmessage. For example, the sending UP small data using the first suspendconfiguration parameters may comprise that the UE perform at least oneof:

-   -   generating an RRC resume request message by setting the contents        of the RRC resume request message where the RRC resume request        message comprises the first resume identity and the first resume        MAC-I;    -   performing ciphering and/or integrity protection with the first        uplink data based on the second security keys; and/or    -   sending at least one of the RRC resume request message and/or        the first uplink data based on the first configuration        parameters.

For example, Msg 3 may comprise the RRC resume request message and thefirst uplink. The sending at least one of the RRC resume request messageand/or the first uplink data based on the first configuration parametersmay comprise at least one of:

-   -   performing header compression of the RRC resume request message        and/or the first uplink data based on the ROHC states (e.g.,        PDCP configuration parameters) of the first restored        configuration parameters; or    -   sending the first uplink data based on QoS flow to DRB mapping        rules of a bearer associated to the first uplink data.

FIG. 21 illustrates an example of CP small data transmission. A UE in anRRC connected state may communicate with a first base station based onfirst configuration parameters and first security keys. The first basestation may send an RRC release message where the RRC release messagemay not comprise suspend configuration parameters. In response ofreceiving the RRC release message, the UE may perform the releasing RRCconnection based on the RRC release message. For example, the releasingRRC connection based on the RRC release message may comprise that UEperforms at least one of:

-   -   discarding uplink data in uplink buffer;    -   discarding UE inactive AS context and current security Keys;    -   releasing all radio resources for all bearers; and/or    -   transitioning to RRC idle state.

The UE in the RRC idle state may send CP small data via control plane.For example, the sending CP small data via control plane may comprisethat the UE perform at least one of:

-   -   generating an RRC early data request message comprising the        first uplink data; and/or    -   sending the an RRC early data request message.

FIG. 22 illustrates an example of consecutive UP small datatransmissions. A UE in an RRC connected state may communicate with afirst base station via cell 1 based on first configuration parametersand first security keys. The first base station may send an RRC releasemessage comprising first suspend configuration parameters where thefirst suspend configuration parameters comprises a first NCC value and afirst resume identity (ID). Based on the first suspend configurationparameters, the UE may perform the suspending RRC connection based onthe first suspend configuration parameters. The UE may transition to anRRC idle state or an RRC inactive state. Based on the cell selectionprocedure, the UE in the RRC idle state or the RRC inactive state mayselect a cell 2 of a second base station (a target base station). The UEmay perform the initiating UP small data transmission using the firstsuspend configuration parameters with the second base station via thecell 2. In response to the initiating UP small data transmission usingthe first suspend configuration parameters, the UE may perform thesending UP small data using the first suspend configuration parameterswith the second base station via the cell 2. The second base station maycheck whether the UE context of the UE is locally available. Based onthe UE context being not locally available, the target base station mayperform a retrieve UE context procedure by sending a retrieve UE contextrequest message to the first base station (the last serving basestation) of the UE. The UE may receive an RRC release message comprisinga second suspend configuration parameters where the second suspendconfiguration parameters comprise a second NCC value and a second resumeID. For example, the UE may receive the RRC release message via the cell2 from either the first base station or the second base station. Basedon the second suspend configuration parameters, the UE may performsuspending RRC connection based on the second suspend configurationparameter. For example, based on the RRC release message, the UE maytransit an RRC state of the UE from RRC inactive state back to RRCinactive state or from RRC idle state back to RRC idle state.

The small data transmission may comprise at least one of early datatransmission (EDT) and preconfigured uplink resource (PUR) transmission(transmission using the PUR). The EDT may comprise random accessprocedure while the PUR may not comprise the random access procedure.For the small data transmission, the UE in an RRC idle state or an RRCinactive state may need uplink resource (grant) to send uplink data. Theuplink resource may comprise dynamic uplink resource or pre-configureduplink resource from a base station. For the EDT, the UE may receive theuplink resource (e.g., the dynamic uplink resource) in response to arandom access preamble configured for EDT and requesting the uplinkresource.

The UP small data transmission may comprise UP EDT and UP PUR. The CPsmall data transmission may comprise CP EDT and CP PUR.

A UE may determine to perform initiating small data transmission for EDTbased on EDT conditions being met. The EDT conditions may comprise atleast one of:

-   -   for mobile originating calls, the size of the resulting MAC PDU        including the total uplink data is expected to be smaller than        or equal to largest transport block size (TBS) for Msg 3        applicable to a UE performing EDT; and/or    -   establishment or resumption request is for mobile originating        calls and the establishment cause is mo data or mo exception        data or delay tolerant access.

A UE may determine to perform initiating small data transmission for UPEDT based on UP EDT conditions being met. The UP EDT conditions maycomprise the EDT conditions and at least one of:

-   -   the UE supports UP EDT;    -   system information of a serving cell indicates UP EDT support;        and/or    -   the UE has a stored NCC value provided in the RRC release        message comprising suspend configuration parameters during the        preceding suspend procedure.

A UE may determine to perform sending CP small data via control planefor CP EDT based on CP EDT conditions being met. The CP EDT conditionsmay comprise the EDT conditions and at least one of:

-   -   the UE supports CP EDT; or    -   system information of a serving cell indicates CP EDT support.

FIG. 23 illustrates an example diagram of UP EDT and CP EDT. A UE in anRRC connected state may communicate with a first base station based onfirst configuration parameters and first security keys. The first basestation may send an RRC release message to the UE. Based on receivingthe RRC release message comprising the first suspend configurationparameters, the UE may perform the suspending RRC connection based onthe first suspend configuration parameters. The UE may transition to anRRC idle state or an RRC inactive state. Based on the RRC releasemessage, the UE may perform a cell (re)selection procedure. Based on thecell (re)selection procedure, the UE in an RRC idle state or an RRCinactive state may select a cell 2 of a second base station (a targetbase station). The UE in an RRC idle state or an RRC inactive state maydetermine to perform the initiating UP small data transmission based onthe UP EDT conditions being met. Based on the determining to perform theinitiating UP small data transmission, the UE in an RRC idle state or anRRC inactive may perform the initiating UP small data transmission usingthe first suspend configuration parameters. In response to theinitiating UP small data transmission, the UE in an RRC idle state or anRRC inactive may perform EDT RACH procedure. Based on the EDT RACHprocedure, the UE may select a random access preamble configured for EDTand send the random access preamble to the second base station via thecell 2. In response to the random access preamble configured for EDT,the UE in an RRC idle state or an RRC inactive may receive (dynamic)uplink resource for EDT. Based on the uplink resource for EDT, the UE inan RRC idle state or an RRC inactive may perform the sending UP smalldata using the first suspend configuration parameters. For example, theUE in an RRC idle state or an RRC inactive may send uplink data usingthe uplink resource for EDT.

In FIG. 23 , a UE in an RRC connected state may communicate with a firstbase station based on first configuration parameters and first securitykeys. The first base station may send an RRC release message to the UE.Based on receiving the RRC release message not comprising the firstsuspend configuration parameters, the UE may perform the releasing RRCconnection. The UE may transition to an RRC idle state or an RRCinactive state. Based on the RRC release message, the UE may perform acell (re)selection procedure. Based on the cell (re)selection procedure,the UE in an RRC idle state may select a cell 2 of a second base station(a target base station). The UE in an RRC idle state may determine toperform the sending CP small data via control plane based on the CP EDTconditions being met. Based on the determining, the UE in an RRC idlemay perform EDT RACH procedure. Based on the EDT RACH procedure, the UEmay select a random access preamble configured for EDT and send therandom access preamble to the second base station via the cell 2. Inresponse to the random access preamble configured for EDT, the UE in anRRC idle state may receive (dynamic) uplink resource for EDT. Based onthe uplink resource for EDT, the UE in an RRC idle state may perform thesending CP small data via control plane. For example, the UE in an RRCidle state may send uplink data using the uplink resource for EDT.

The UE in an RRC idle state or an RRC inactive may receive a responsemessage for at least one of the RRC request message and/or the firstuplink data. The response message may comprise at least one of an RRCresponse message and/or downlink data. The RRC response message maycomprise downlink data. Based on receiving the response message, the UEin an RRC idle state or an RRC inactive may consider (UP or CP) smalldata transmission being successful. Based on the considering, the UE inan RRC idle state or an RRC inactive may empty at least one of uplinkbuffer for the first uplink data and/or uplink buffer for the RRCrequest message. For example, in response to the Msg 3 comprising atleast one the RRC request message and/or the first uplink data, the UEin an RRC idle state or an RRC inactive may receive Msg 4. The Msg 4 maycomprise an RRC response message. Based on receiving the Msg 4, the UEin an RRC idle state or an RRC inactive may consider the (UP or CP)small data transmission being successful. Based on the considering, theUE in an RRC idle state or an RRC inactive may empty at least one ofuplink buffer for the first uplink data and/or uplink buffer for the RRCrequest message. For example, based on the considering, the UE in an RRCidle state or an RRC inactive may flush at least one of HARQ buffer forthe first uplink data and HARQ buffer for the RRC request message.

FIG. 24 illustrates an example of UP EDT. A UE in an RRC connected statemay communicate with a first base station based on first configurationparameters and first security keys. The first base station may send anRRC release message comprising first suspend configuration parameterswhere the first suspend configuration parameters comprises a first NCCvalue and a first resume identity (ID). Based on receiving the firstsuspend configuration parameters, the UE may perform the suspending RRCconnection based on the first suspend configuration parameters. The UEmay transition to an RRC idle state or an RRC inactive state. Based onthe RRC release message, the UE may perform a cell (re)selectionprocedure. Based on the cell (re)selection procedure, the UE in an RRCidle state or an RRC inactive state may select a cell 2 of a second basestation (a target base station). The UE in an RRC idle state or an RRCinactive state may determine to perform the initiating UP small datatransmission based on the UP EDT conditions being met. The UE may have afirst uplink data in uplink buffer. Based on the determining, the UE mayperform the initiating UP small data transmission using the firstsuspend configuration parameters. In response to the initiating UP smalldata transmission, the UE may perform EDT RACH procedure. Based on theEDT RACH procedure, the UE may select a random access preambleconfigured for EDT and send the random access preamble to the secondbase station via the cell 2. In response to the random access preambleconfigured for EDT, the UE may receive uplink resource/grant for EDT.Based on the uplink resource/grant for EDT, the UE may perform thesending UP small data using the first suspend configuration parameters.For example, the UE in an RRC idle state or an RRC inactive may send atleast one of an RRC request message and/or the first uplink data usingthe uplink resource for EDT where the RRC request message may be an RRCresume request message. For example, based on the sending UP small datausing the first suspend configuration parameters, the UE in an RRC idlestate or an RRC inactive may send Msg 3 comprising CCCH SDU and/or DTCHSDU where the CCCH SDU comprises an RRC resume request message and theDTCH SDU comprises the first uplink data. For example, the RRC resumerequest message may comprise the first resume ID and first MAC-I wherethe UE derives the first MAC-I based on the first suspend configurationparameters. The UE in an RRC idle state or an RRC inactive may receive aresponse message in response to at least one of the RRC resume requestmessage and/or the first uplink data. The response message may comprisean RRC release message. The RRC release message may comprise downlinkdata. Based on receiving the response message, the UE in an RRC idlestate or an RRC inactive may consider UP small data transmission beingsuccessful. Based on the considering, the UE in an RRC idle state or anRRC inactive may empty at least one of uplink buffer for the firstuplink data. For example, in response to the Msg 3 comprising at leastone the RRC resume request message and/or the first uplink data, the UEin an RRC idle state or an RRC inactive may receive Msg 4. The Msg 4 maycomprise an RRC release message. Based on receiving the Msg 4, the UE inan RRC idle state or an RRC inactive may consider the UP small datatransmission being successful. Based on the considering, the UE in anRRC idle state or an RRC inactive may empty at least one of uplinkbuffer for the first uplink data and/or uplink buffer for the RRCrequest message. For example, based on the considering, the UE in an RRCidle state or an RRC inactive may flush at least one of HARQ buffer forthe first uplink data and/or HARQ buffer for the RRC request message.Based on the RRC release message not comprising a second suspendconfiguration parameters, the UE in an RRC idle state or an RRC inactivemay perform the releasing RRC connection. For example, based on thereleasing RRC connection, the UE in an RRC idle state or an RRC inactivemay transition to an RRC idle state. Based on the RRC release messagecomprising a second suspend configuration parameters, the UE in an RRCidle state or an RRC inactive may perform the suspending RRC connectionusing the second suspend configuration parameters. For example, based onthe suspending RRC connection using the second suspend configurationparameters, the UE may transit an RRC state of the UE from RRC inactivestate back to RRC inactive state or from RRC idle state back to RRC idlestate.

For the PUR transmission, a UE may transmit PUR configuration requestmessage to a base station where the PUR configuration request messagemay comprise at least one of:

-   -   requested number of PUR occasions where the number may be one or        infinite;    -   requested periodicity of PUR;    -   requested transport block size (TBS) for PUR; and/or    -   requested time offset for a first PUR occasion.

The base station may send PUR configuration parameters comprising thepreconfigured uplink resource to the UE. For example, in response to thePUR configuration request message, the base station may send PURconfiguration parameters comprising the preconfigured uplink resource tothe UE. For example, the base station may send an RRC release messagecomprising the PUR configuration parameters.

The PUR configuration parameters may comprise at least one of:

-   -   an indication to setup or release PUR configuration parameters;    -   number of PUR occasions;    -   PUR resource identifier (PUR-RNTI);    -   value of the time offset for a first PUR occasion (PUR start        time);    -   periodicity of PUR resource (PUR periodicity);    -   duration of PUR response window (PUR response window time);    -   threshold(s) of change in serving cell RSRP in dB for TA        validation (PUR change threshold(s)) where the thresholds        comprise RSRP increase threshold and RSRP decrease threshold;    -   value of time alignment timer for PUR; and/or    -   physical configuration parameters for PUR.

The physical configuration parameters for PUR may comprises at least oneof:

-   -   PUSCH configuration parameters for PUR;    -   PDCCH configuration parameters for PUR;    -   PUCCH configuration parameters for PUR;    -   downlink carrier configuration parameters used for PUR; and/or    -   uplink carrier frequency of the uplink carrier used for PUR

A UE may determine to perform initiating UP small data transmission forPUR based on PUR conditions being met. The PUR conditions may compriseat least one of:

-   -   the UE has a valid PUR configuration parameters;    -   the UE has a valid timing alignment (TA) value; and/or    -   establishment or resumption request is for mobile originating        calls and the establishment cause is mo data or mo exception        data or delay tolerant access.

A UE may determine to perform initiating UP small data transmission forUP PUR based on UP PUR conditions being met. The UP PUR conditions maycomprise the PUR conditions and at least one of:

-   -   the UE supports UP PUR;    -   system information of a serving cell indicates UP PUR support;        and/or    -   the UE has a stored NCC value provided in the RRC release        message comprising suspend configuration parameters during the        preceding suspend procedure.

A UE may determine to perform sending CP small data via control planefor CP PUR based on CP PUR conditions being met. The CP PUR conditionsmay comprise the PUR conditions and at least one of:

-   -   the UE supports CP PUR;    -   system information of a serving cell indicates CP PUR support;        and/or    -   the size of the resulting MAC PDU including the total uplink        data is expected to be smaller than or equal to the TBS        configured for PUR.

The UE may determine the timing alignment value for small datatransmission for PUR to being valid based on TA validation conditionsfor PUR being met. The TA validation conditions for PUR may comprise atleast one of:

-   -   the time alignment timer for PUR is running; or    -   serving cell RSRP has not increased by more than the RSRP        increase threshold and has not decreased by more than the RSRP        increase threshold.

In response to receiving the PUR configuration parameters, the UE maystore or replace PUR configuration parameters provided by the PURconfiguration parameters based on the indication requesting to setup PURconfiguration parameters. In response to receiving the PUR configurationparameters, the UE may start a time alignment timer for PUR with thevalue of time alignment timer for PUR and configure the PURconfiguration parameters. For example, based on the indicationrequesting to setup PUR configuration parameters, the UE may start atime alignment timer for PUR with the value of time alignment timer forPUR and configure the PUR configuration parameters. In response toreceiving the PUR configuration parameters, the UE may discard PURconfiguration parameters based on the indication requesting to releasePUR configuration parameters. In response to the configuring the PURconfiguration parameters, the UE may generate preconfigured uplinkresource/grant for PUR based on the PUR configuration parameters. Forexample, based on the PUR configuration parameters, the UE may determinewhen generating the preconfigured uplink resource/grant. For example,based on the PUR start time and the PUR periodicity, the UE maydetermine when generating the preconfigured uplink resource/grant. Forexample, based on the PUSCH configuration parameters, the UE maydetermine (transport blocks for) the preconfigured uplinkresource/grant. For example, based on the PUSCH configurationparameters, the UE may determine (transport blocks for) thepreconfigured uplink resource/grant.

FIG. 25 illustrates an example of UP PUR and CP PUR. A UE in an RRCconnected state may communicate with a first base station based on firstconfiguration parameters and first security keys. The first base stationmay send an RRC release message to the UE. Based on receiving the RRCrelease message comprising the first suspend configuration parameters,the UE may perform the suspending RRC connection based on the firstsuspend configuration parameters. The UE may transition to an RRC idlestate or an RRC inactive state. The UE may receive PUR configurationparameters via previous RRC release message. The previous RRC releasemessage may be the RRC release message. In response to receiving the PURconfiguration parameters, the UE in an RRC idle state or an RRC inactivestate may start a time alignment timer for PUR with the value of timealignment timer for PUR and configure the PUR configuration parameters.In response to the configuring the PUR configuration parameters, the UEan RRC idle state or an RRC inactive state may generate preconfigureduplink resource/grant for PUR based on the PUR configuration parameters.Based on the RRC release message, the UE in an RRC idle state or an RRCinactive state may perform a cell (re)selection procedure. Based on thecell (re)selection procedure, the UE in an RRC idle state or an RRCinactive state may select a cell 2 of a second base station (a targetbase station). The UE in an RRC idle state or an RRC inactive state maydetermine to perform the initiating UP small data transmission based onthe UP PUR conditions being met. Based on the determining to perform theinitiating UP small data transmission, the UE in an RRC idle state or anRRC inactive may perform the initiating UP small data transmission usingthe first suspend configuration parameters. Based on the (preconfigured)uplink resource for PUR, the UE in an RRC idle state or an RRC inactivemay perform the sending UP small data using the first suspendconfiguration parameters. For example, the UE in an RRC idle state or anRRC inactive may send uplink data using the uplink resource for PUR.

In FIG. 25 , a UE in an RRC connected state may communicate with a firstbase station based on first configuration parameters and first securitykeys. The first base station may send an RRC release message to the UE.Based on receiving the RRC release message not comprising the firstsuspend configuration parameters, the UE may perform the releasing RRCconnection based on the RRC release message. The UE may transition to anRRC idle state. The UE may receive PUR configuration parameters viaprevious RRC release message. The previous RRC release message may bethe RRC release message. In response to receiving the PUR configurationparameters, the UE in an RRC idle state may start a time alignment timerfor PUR with the value of time alignment timer for PUR and configure thePUR configuration parameters. In response to the configuring the PURconfiguration parameters, the UE an RRC idle state may generatepreconfigured uplink resource/grant for PUR based on the PURconfiguration parameters. Based on the RRC release message, the UE anRRC idle state may perform a cell (re)selection procedure. Based on thecell (re)selection procedure, the UE in an RRC idle state may select acell 2 of a second base station (a target base station). The UE in anRRC idle state may determine to perform the sending CP small data viacontrol plane based on the CP PUR conditions being met. Based on thedetermining, the UE in an RRC idle state may perform the sending CPsmall data via control plane. For example, based on the (preconfigured)uplink resource for PUR, the UE in an RRC idle state may perform thesending CP small data via control plane. For example, the UE in an RRCidle state may send at least one of an RRC request message and/or uplinkdata using the uplink resource for PUR. For example, the RRC requestmessage may be an RRC early data request message and/or comprise theuplink data.

After the sending UP small data using PUR (or for PUR) or CP small datavia control plane using PUR (or for PUR), the UE (UE-MAC entity) maystart PUR response window timer with the PUR response window time. Forexample, after subframe containing the end of sending at least one ofthe RRC request message and/or the uplink data via PUSCH, plus time gap(e.g., 4 subframes), the UE (UE-MAC entity) in an RRC idle state or anRRC inactive state may start PUR response window timer with the PURresponse window time. Based on the starting, the UE may monitor PDCCHidentified by PUR RNTI until the PUR response window timer is expired.The UE (UE-MAC entity) in an RRC idle state or an RRC inactive state mayreceive a response message in response to at least one of the RRCrequest message and/or the uplink data. The response message maycomprise at least one of a downlink message (e.g., DCI) identified bythe PUR RNTI on the PDCCH, an RRC response message for the RRC requestmessage and/or downlink data. The downlink message may comprise at leastone of:

-   -   a downlink message indicating an uplink grant for        retransmission;    -   a downlink message indicating L1 (layer 1) ack for PUR;    -   a downlink message indicating fallback for PUR; and/or    -   a downlink message indicating PDCCH transmission (downlink grant        or downlink assignment) addressed to the PUR RNTI and/or MAC PDU        comprising the uplink data being successfully decoded.

Based on receiving the downlink message indicating an uplink grant forretransmission, the UE may restart the PUR response window timer at lastsubframe of a PUSCH transmission indicating the uplink grant, puls timegap (e.g., 4 subframes). Based on the restarting, the UE in an RRC idlestate or an RRC inactive state may monitor PDCCH identified by PUR RNTIuntil the PUR response window timer is expired. Based on receiving thedownlink message indicating L1 (layer 1) ack for PUR, the UE in an RRCidle state or an RRC inactive state may stop the PUR response windowtimer and consider the small data transmission using PUR successful.Based on receiving the downlink message indicating fallback for PUR, theUE in an RRC idle state or an RRC inactive state may stop the PURresponse window timer and consider the small data transmission using PURbeing failed. Based on receiving the downlink message indicating PDCCHtransmission (downlink grant or downlink assignment) addressed to thePUR RNTI and/or MAC PDU comprising the uplink data being successfullydecoded, the UE in an RRC idle state or an RRC inactive state may stopthe PUR response window timer and consider the small data transmissionusing PUR successful. Based on the PDCCH transmission, the UE in an RRCidle state or an RRC inactive state may receive at least one of an RRCresponse message and downlink data wherein the RRC response message atleast one of an RRC release message or an RRC early data completemessage. Based on not receiving any downlink message until the PURresponse window timer being expired, the UE in an RRC idle state or anRRC inactive state may consider the small data transmission using PURbeing failed. Based on considering the small data transmission using PURbeing failed, the UE may perform random access procedure. For example,the random access procedure may comprise EDT RACH procedure.

FIG. 26 illustrates an example of UP PUR. A UE in an RRC connected statemay communicate with a first base station based on first configurationparameters and first security keys. The first base station may send anRRC release message comprising first suspend configuration parameterswhere the first suspend configuration parameters comprises a first NCCvalue and a first resume identity (ID). Based on receiving the firstsuspend configuration parameters, the UE may perform the suspending RRCconnection based on the first suspend configuration parameters. The UEmay transition to an RRC idle state or an RRC inactive state. The UE mayreceive PUR configuration parameters via previous RRC release message.The previous RRC release message may be the RRC release message. Inresponse to receiving the PUR configuration parameters, the UE in an RRCidle state or an RRC inactive state may start a time alignment timer forPUR with the value of time alignment timer for PUR and configure the PURconfiguration parameters. In response to the configuring the PURconfiguration parameters, the UE an RRC idle state or an RRC inactivestate may generate preconfigured uplink resource/grant for PUR based onthe PUR configuration parameters. Based on the RRC release message, theUE may perform a cell (re)selection procedure. Based on the cell(re)selection procedure, the UE in an RRC idle state or an RRC inactivestate may select a cell 2 of a second base station (a target basestation). The UE in an RRC idle state or an RRC inactive may have afirst uplink data in uplink buffer. The UE in an RRC idle state or anRRC inactive state may determine to perform the initiating UP small datatransmission based on the UP PUR conditions being met. For example, inresponse to the having the first uplink data or receiving pagingmessage, the UE in an RRC idle state or an RRC inactive state maydetermine to perform the initiating UP small data transmission based onthe UP PUR conditions being met. Based on the determining, the UE mayperform the initiating UP small data transmission using the firstsuspend configuration parameters. Based on the uplink resource/grant forPUR, the UE may perform the sending UP small data using the firstsuspend configuration parameters. For example, the UE in an RRC idlestate or an RRC inactive may send at least one of an RRC resume requestmessage and/or the first uplink data, using the uplink resource for PUR.For example, based on the sending UP small data using the first suspendconfiguration parameters, the UE in an RRC idle state or an RRC inactivemay send Msg 3 comprising at least one of CCCH SDU and/or DTCH SDU wherethe CCCH SDU comprises an RRC resume request message and the DTCH SDUcomprises the first uplink data. For example, the RRC resume requestmessage may comprise the first resume ID and first MAC-I where the UEderives the first MAC-I based on the first suspend configurationparameters. In response to the sending UP small data using PUR, the UE(UE-MAC entity) may start PUR response window timer with the PURresponse window time. Based on the starting, the UE may monitor PDCCHidentified by PUR RNTI until the PUR response window timer is expired.The UE (UE-MAC entity) may receive a downlink message (e.g., DCI)identified by the PUR RNTI on the PDCCH. Based on receiving the downlinkmessage indicating PDCCH transmission (downlink grant or downlinkassignment) addressed to the PUR RNTI and/or MAC PDU comprising theuplink data being successfully decoded, the UE may stop the PUR responsewindow timer and consider the small data transmission using PURsuccessful. Based on the PDCCH transmission, the UE may receive at leastone of an RRC release message and downlink data in response to at leastone of the RRC resume request message and/or the uplink data. Based onthe RRC release message not comprising a second suspend configurationparameters, the UE in an RRC idle state or an RRC inactive may performthe releasing RRC connection. For example, based on the releasing RRCconnection, the UE in an RRC idle state or an RRC inactive maytransition to an RRC idle state. Based on the RRC release messagecomprising a second suspend configuration parameters, the UE in an RRCidle state or an RRC inactive may perform the suspending RRC connectionusing the second suspend configuration parameters. For example, based onthe suspending RRC connection using the second suspend configurationparameters, the UE may transit an RRC state of the UE from RRC inactivestate back to RRC inactive state or from RRC idle state back to RRC idlestate.

FIG. 27 illustrates an example of consecutive UP small datatransmissions. A UE in an RRC connected state may communicate with afirst base station based on first configuration parameters and firstsecurity keys. The first base station may send an RRC release messagecomprising first suspend configuration parameters where the firstsuspend configuration parameters comprises a first NCC value and a firstresume identity (ID). Based on receiving the first suspend configurationparameters, the UE may perform the suspending RRC connection based onthe first suspend configuration parameters. The UE may transition to anRRC idle state or an RRC inactive state. The UE may receive PURconfiguration parameters via previous RRC release message. The previousRRC release message may be the RRC release message. The UE in an RRCidle state or an RRC inactive may have a first uplink data in uplinkbuffer. The UE in an RRC idle state or an RRC inactive state maydetermine to perform the initiating UP small data transmission for afirst small data transmission based on the UP EDT conditions or the UPPUR conditions being met. Based on the determining, the UE may performthe initiating UP small data transmission for the first small datatransmission based on the first suspend configuration parameters. The UEmay have uplink resource for small data transmission based on the EDTRACH or the PUR configuration parameters where the uplink resource forsmall data transmission comprise at least one of the uplink resource forEDT or the (preconfigured) uplink resource for PUR. In response to theinitiating UP small data transmission for the first small datatransmission, the UE in an RRC idle state or an RRC inactive may performthe sending small data for the first small data transmission using thefirst suspend configuration parameters. For example, the UE may send atleast one of the first uplink data and/or the RRC resume requestmessage, using the uplink resource for small data transmission. The UEmay receive a response message in response to at least one of the firstuplink data and/or the RRC resume request message. The response messagemay comprise at least one of a downlink message, an RRC release messageand/or downlink data. The RRC release message may comprise downlinkdata. Based on receiving the response message, the UE in an RRC idlestate or an RRC inactive may consider UP small data transmission for thefirst small data transmission being successful. Based on theconsidering, the UE in an RRC idle state or an RRC inactive may empty atleast one of uplink buffer for the first uplink data and/or uplinkbuffer for the RRC resume request message. For example, in response tothe Msg 3 comprising at least one of the first uplink data and/or theRRC resume request message, the UE in an RRC idle state or an RRCinactive may receive Msg 4. The Msg 4 may comprise at least one of thedownlink message, the RRC release message and/or downlink data. Based onreceiving the Msg 4, the UE in an RRC idle state or an RRC inactive mayconsider the UP small data transmission via Msg 3 being successful.Based on the considering, the UE in an RRC idle state or an RRC inactivemay empty at least one of uplink buffer for the first uplink data and/oruplink buffer for the RRC resume request message. For example, based onthe considering, the UE in an RRC idle state or an RRC inactive mayflush at least one of HARQ buffer for the first uplink data and/or HARQbuffer for the RRC resume request message. Based on the RRC releasemessage comprising a second suspend configuration parameters, the UE inan RRC idle state or an RRC inactive may perform the suspending RRCconnection using the second suspend configuration parameters. Forexample, based on the suspending RRC connection using the second suspendconfiguration parameters, the UE may transit an RRC state of the UE fromRRC inactive state back to RRC inactive state or from an RRC idle stateback to an RRC idle state. The UE in an RRC idle state or an RRCinactive may have a second uplink data in uplink buffer. The UE in anRRC idle state or an RRC inactive state may determine to perform theinitiating UP small data transmission for a second small datatransmission based on the UP EDT conditions or the UP PUR conditionsbeing met. Based on the determining, the UE may perform the initiatingUP small data transmission for the second small data transmission basedon the second suspend configuration parameters. In response to theinitiating UP small data transmission for the second small datatransmission, the UE may have uplink resource for small datatransmission based on the EDT RACH or the PUR configuration parameters.Based on the uplink resource, the UE in an RRC idle state or an RRCinactive may perform sending small data for the second small datatransmission using the second suspend configuration parameters.

Small data transmission may comprise at least one of initiating smalldata transmission, sending small data and receiving a response message.UP small data transmission may comprise at least one of initiating UPsmall data transmission, sending UP small data and receiving a responsemessage. CP small data transmission may comprise at least one of sendingCP small data via control plane and receiving a response message.

A UE in an RRC idle state or an RRC inactive may have a first uplinkdata and a second uplink data. The UE in an RRC idle state or an RRCinactive may not send both of the first uplink data and the seconduplink data using uplink resource for small data transmission where theuplink resource comprise at least one of the uplink resource for EDT orthe (preconfigured) uplink resource for PUR. For example, the UE in anRRC idle state or an RRC inactive may send the first uplink data usingthe uplink resource for small data transmission but not send both of thefirst uplink data and the second uplink data using the uplink resourcefor small data transmission. For example, the size of the resulting MACPDU including the first uplink data may be expected to be smaller thanor equal to the TBS configured for PUR. The size of the resulting MACPDU including the first uplink data may be expected to be smaller thanor equal to largest transport block size (TBS) for Msg 3 applicable to aUE performing EDT. The UE in an RRC idle state or an RRC inactive maysend BSR requesting uplink resource for the second uplink data. Forexample, the UE in an RRC idle state or an RRC inactive may send the BSRwith the first uplink and/or the RRC request message using the uplinkresource for small data transmission. For example, the UE may send theBSR with the first uplink and/or the RRC request message using uplinkresource for small data transmission via Msg 3. Based on sending atleast one of the BSR, the first uplink and/or the RRC request message,the UE in an RRC idle state or an RRC inactive may receive a responsemessage in response to the first uplink and/or the RRC request message.The response message may comprise at least one of an RRC responsemessage requesting to establish/resume RRC connection, and uplinkresource for the second uplink data. Based on the response message, theUE in an RRC idle state or an RRC inactive may consider the small datatransmission being successful. Based on receiving the RRC responsemessage, the UE in an RRC idle state or an RRC inactive may transitionto RRC connected state from an RRC idle state or an RRC inactive state.Based on the transitioning, the UE in the RRC connected state may sendthe second uplink data using the uplink resource for the second uplinkdata. The transitioning to the RRC connected state may cause overheadsand complexity. For example, the RRC response message may compriseconfiguration parameters. Based on receiving the configurationparameters, the UE in the RRC connected state may configure theconfiguration parameters. Based on the configuring, the UE in the RRCconnected state may perform operation for the configuration parameters.For example, the operation may comprise at least one of monitoring,measurement, reporting. Based on the second uplink data being small sizedata, the UE in an RRC idle state or an RRC inactive may avoid thetransitioning. A base station may allow the UE in an RRC idle state oran RRC inactive to perform subsequent transmission without thetransitioning to an RRC connected state after the considering small datatransmission being successful. Based on the subsequent transmissionallow information, the UE may send the second uplink data withouttransitioning to the RRC connected state.

FIG. 28 illustrates an example of subsequent transmission after UP smalldata transmission. A UE in an RRC connected state may communicate with afirst base station based on first configuration parameters and firstsecurity keys. The first base station may send an RRC release messagecomprising first suspend configuration parameters where the firstsuspend configuration parameters comprises a first NCC value and a firstresume identity (ID). Based on receiving the first suspend configurationparameters, the UE may perform the suspending RRC connection based onthe first suspend configuration parameters. The UE may transition to anRRC idle state or an RRC inactive state. The UE may receive PURconfiguration parameters via previous RRC release message. The previousRRC release message may be the RRC release message. Based on the RRCrelease message, the UE may perform a cell (re)selection procedure.Based on the cell (re)selection procedure, the UE in an RRC idle stateor an RRC inactive state may select a cell 2 of a second base station (atarget base station). The UE in an RRC idle state or an RRC inactive mayhave a first uplink data and a second uplink data in uplink buffer. TheUE in an RRC idle state or an RRC inactive may have uplink resource forsmall data transmission based on the EDT RACH or the PUR configurationparameters where the uplink resource for small data transmissioncomprise at least one of the uplink resource for EDT or the(preconfigured) uplink resource for PUR. The UE in an RRC idle state oran RRC inactive may not send both of the first uplink data and thesecond uplink data via (or during) small data transmission using theuplink resource for small data transmission. For example, the UE in anRRC idle state or an RRC inactive may send the first uplink data via (orduring) small data transmission using the uplink resource for small datatransmission but not send both of the first uplink data and the seconduplink data using the uplink resource for small data transmission. TheUE in an RRC idle state or an RRC inactive state may determine toperform the initiating UP small data transmission for a first small datatransmission. In response to the initiating UP small data transmissionfor the first small data transmission, the UE in an RRC idle state or anRRC inactive may perform the sending small data for the first small datatransmission using the first suspend configuration parameters. Forexample, the UE in an RRC idle state or an RRC inactive may send (e.g.,in Msg 3) at least one of the first uplink data, the RRC resume requestmessage and BSR requesting uplink resource for the second uplink data,using the uplink resource for small data transmission. The UE in an RRCidle state or an RRC inactive may receive a first response message(e.g., in Msg 4) in response to the first uplink data, the RRC resumerequest message and/or the BSR. The first response message may comprisedownlink data, uplink resource for the second uplink data,acknowledgment for the first uplink data. Based on the first responsemessage, the UE in an RRC idle state or an RRC inactive may consider thesmall data transmission being successful. Based on the considering, theUE in an RRC idle state or an RRC inactive may empty at least one ofuplink buffer for the first uplink data and/or uplink buffer for the RRCresume request message. For example, based on the considering, the UE inan RRC idle state or an RRC inactive may flush at least one of HARQbuffer for the first uplink data and/or HARQ buffer for the RRC resumerequest message. A base station may allow the UE in an RRC idle state oran RRC inactive to perform (or initiate) subsequent transmission withoutthe transitioning to an RRC connected state after the considering smalldata transmission being successful where the base station may be thefirst base station or the second base station. Based on the subsequenttransmission allow information, the UE in an RRC idle state or an RRCinactive may perform (or initiate) the subsequent transmission. Forexample, the performing the subsequent transmission may comprise sendingsubsequent data (e.g., the second uplink data) (e.g., in Msg 5) usingthe uplink resource for the second uplink data without transitioning toan RRC connected state. In response to the second uplink data, the UEmay receive a second response message (e.g. in Msg 6). The secondresponse message may comprise at least acknowledgment for the firstuplink data. Based on receiving the second response message, the UE mayconsider the subsequent transmission being successful. Based on theconsidering the subsequent transmission being successful, the UE in anRRC idle state or an RRC inactive may empty uplink buffer for the seconduplink data. For example, based on the considering the subsequenttransmission being successful, the UE in an RRC idle state or an RRCinactive may flush HARQ buffer for the second uplink data.

A base station (e.g., the second base station) may send an RRC releasemessage to a UE. For the small data transmission (e.g., UP EDT in FIG.24 or UP PUR in FIG. 26 ), the base station sends the RRC releasemessage via Msg 4 (e.g., via a first response message). For subsequenttransmission in FIG. 28 , the second base station may send an RRCrelease message either via Msg 4 (e.g., a first response message) or Msg6 (e.g., a last response/downlink message). The second based station maysend the RRC release message via the Msg 4 because radio channelcondition at the Msg 4 is reliable. For example, the UE may determinesmall data transmission based on at least radio channel condition withthe cell 2 of the second base station being good enough for the smalldata transmission. The radio channel condition at the Msg 4 may belikely to be good and reliable as compared to the Msg 6.

In existing technologies, a UE may send or receive a small amount ofdata without transitioning from an RRC idle or inactive state to an RRCconnected state. The small data may be transmitted or received with RRCmessages. If the small amount of data exceeds a threshold amount of data(e.g., an amount of data that will fit in an RRC message), it may bedivided into portions and transmitted in a plurality of small datatransmissions. If the wireless device receives an RRC release messagefrom the base station (e.g., due to deteriorating radio conditions),then existing mechanisms may dictate that the UE perform a number ofactions. One of the actions may be to discard uplink data. As anexample, the wireless device may transmit a first portion of small datato the base station and subsequently receive an RRC release message fromthe base station. Based on the release message, the wireless device maydiscard a second portion of the small data that resides in the uplinkbuffer. When the small data transmissions resume, data that has beendiscarded from the uplink buffer (e.g., the second portion of the smalldata) may need to be regenerated, causing delay.

In embodiments of the disclosure, a wireless device may transmitsubsequent SDT data prior to receiving an RRC release message. Thewireless device may perform an SDT procedure while in an RRCnon-connected state (e.g., RRC inactive and/or RRC idle). The wirelessdevice may transmit first data associated with the SDT procedure and anRRC request message. The wireless device may receive, while in the RRCnon-connected state, an indication of an uplink resource. The indicationof the uplink resource may be transmitted in response to thetransmitting of the first data and/or the RRC request message. Theuplink resource may be used to transmit subsequent SDT data, forexample, second data associated with the SDT procedure. The wirelessdevice may receive an RRC release message after transmitting the seconddata associated with the SDT procedure. If the wireless device hadreceived the RRC release message prior to receiving the indication ofthe uplink resource (as may have occurred in existing technologies), thewireless device may have discarded the second data. Based on the uplinkresource, the wireless device may have completed or partially completedthe SDT procedure (for example, by transmitting additional small databefore discarding).

In embodiments of the disclosure, a wireless device may determine tocontinue small data transmission after receiving an RRC release message.For example, the wireless device may delay actions normally performed inresponse to receiving of an RRC release message until one or moreadditional small data transmissions are completed. In response to thecompletion of the one or more additional transmissions, the wirelessdevice may perform the delayed wireless device actions. By delaying theactions based on the receiving of the RRC release message, the wirelessdevice can complete the small data transmissions before performing theactions. As a result, uplink data can be transmitted without delay andthere is no need to regenerate discarded uplink data.

In existing technologies, an RRC release message may include suspendconfiguration parameters. Suspend configuration parameters are used, forexample, to perform RRC signaling associated with reconnection. Forexample, the suspend configuration parameters may comprise a resume IDfor the wireless device. The suspend configuration parameters maycomprise a next hop chaining count (NCC) value. The wireless device mayuse the NCC value to update security keys. For security purposes (e.g.,prevention of piracy of the wireless device's resume ID), existingprotocols may dictate that suspend configuration parameters be used onlyonce (e.g., no re-use of security keys). Accordingly, in existingtechnologies, after suspend configuration parameters are received, thewireless device may use the suspend configuration parameters for atransmission of small data. The wireless device may wait for new suspendconfiguration parameters before transmitting a next portion of the smalldata. This process consumes processing power and creates signalingoverhead.

In embodiments of the disclosure, a wireless device may continue to usefirst suspend configuration parameters for small data transmission evenafter receiving new suspend configuration parameters. For example, thewireless device may receive first suspend configuration parameters. Thewireless device may transmit a first portion of small data using thefirst suspend configuration parameters. For example, the wireless devicemay derive second security keys using the first suspend configurationparameters (e.g., based on a first NCC value). The wireless device maytransmit the first portion with a first RRC resume request message(e.g., based on the first NCC value and/or the second security keys, andcomprising a first resume ID). The wireless device may receive an RRCrelease message comprising second suspend configuration parameters.After receiving the second suspend configuration parameters, thewireless device may transmit at least one additional portion of smalldata (e.g., second portion, third portion, etc.) using the first suspendconfiguration parameters. For example, the wireless device may transmitthe at least one additional portion of small data without an RRC messagebased on the first NCC value and/or the second security keys. Forexample, the wireless device may transmit the at least one additionalportion of small data with an RRC message based on the first NCC valueand/or the second security keys. In an example, the RRC message with theat least one additional portion of small data may not be an RRC resumerequest message and/or may not include the first resume ID. Additionallyor alternatively, after receiving the second suspend configurationparameters, the wireless device may also transmit a portion of smalldata with a second RRC resume request message based on the secondsuspend configuration parameters (e.g., based on a second NCC valueand/or second third keys, and comprising a second resume ID). By reusingthe first suspend configuration parameters to transmit additionalportions of the small data, the wireless device can complete a givennumber of small data transmissions based on fewer suspend configurationparameters. As a result, signaling overhead can be reduced and thenetwork may consume less power processing suspend configurations.

FIG. 29 illustrates an example of (first) response message comprisingRRC release message in subsequent transmission. A UE in an RRC connectedstate may communicate with a first base station based on firstconfiguration parameters and first security keys. The first base stationmay send an RRC release message comprising first suspend configurationparameters where the first suspend configuration parameters comprises afirst NCC value and a first resume identity (ID). Based on receiving thefirst suspend configuration parameters, the UE may perform thesuspending RRC connection based on the first suspend configurationparameters. The UE may transition to an RRC idle state or an RRCinactive state. Based on the RRC release message, the UE may perform acell (re)selection procedure. Based on the cell (re)selection procedure,the UE in an RRC idle state or an RRC inactive state may select a cell 2of a second base station (a target base station). The UE in an RRC idlestate or an RRC inactive may have a first uplink data and a seconduplink data in uplink buffer. The UE in an RRC idle state or an RRCinactive may have uplink resource for small data transmission based onthe EDT RACH or the PUR configuration parameters where the uplinkresource for small data transmission comprises at least one of theuplink resource for EDT or the (preconfigured) uplink resource for PUR.The UE in an RRC idle state or an RRC inactive may not send both of thefirst uplink data and the second uplink data via (or during) small datatransmission using the uplink resource for small data transmission. Forexample, the UE in an RRC idle state or an RRC inactive may send thefirst uplink data via (or during) small data transmission using theuplink resource for small data transmission but not send both of thefirst uplink data and the second uplink data using the uplink resourcefor small data transmission. The UE in an RRC idle state or an RRCinactive state may determine to perform the initiating UP small datatransmission for a small data transmission. In response to theinitiating UP small data transmission for the small data transmission,the UE in an RRC idle state or an RRC inactive may perform the sendingsmall data for the first small data transmission using the suspendconfiguration parameters. For example, the UE in an RRC idle state or anRRC inactive may send (e.g., in Msg 3) at least one of the first uplinkdata, the RRC resume request message and BSR requesting uplink resourcefor the second uplink data, using the uplink resource for small datatransmission. The UE in an RRC idle state or an RRC inactive may receivea response message (e.g., in Msg 4) in response to the first uplinkdata, the RRC resume request message and/or the BSR. The responsemessage may comprise downlink data, uplink resource for the seconduplink data, acknowledgment for the first uplink data. Based on theresponse message, the UE in an RRC idle state or an RRC inactive mayconsider the small data transmission being successful. Based on theconsidering, the UE in an RRC idle state or an RRC inactive may empty atleast one of uplink buffer for the first uplink data and/or uplinkbuffer for the RRC resume request message. For example, based on theconsidering, the UE in an RRC idle state or an RRC inactive may flush atleast one of HARQ buffer for the first uplink data and/or HARQ bufferfor the RRC resume request message. A base station may allow the UE inan RRC idle state or an RRC inactive to perform subsequent transmissionwithout the transitioning to an RRC connected state after theconsidering small data transmission being successful where the basestation may be the first base station or the second base station. Basedon the subsequent transmission allow information, the UE in an RRC idlestate or an RRC inactive may perform sending subsequent data (e.g., thesecond uplink data) using the uplink resource for the second uplink datawithout transitioning to an RRC connected state.

In an example, the response message (e.g. Msg 4) may further comprise anRRC release message. Based on the RRC release message, the UE mayperform the UE actions for the RRC release message. Based on the UEactions (e.g., MAC reset or re-establishing RLC entities), the UE in anRRC idle state or an RRC inactive state may discard the second uplinkdata in uplink buffer and discard the uplink resource for the seconduplink data. The UE may not send the second uplink data using the uplinkresource for the second uplink via (or during) the subsequenttransmission.

FIG. 30 illustrates an example of (first) response message comprisingRRC release message comprising suspend configuration parameters insubsequent transmission. A UE in an RRC connected state may communicatewith a first base station based on first configuration parameters andfirst security keys. The first base station may send an RRC releasemessage comprising first suspend configuration parameters where thefirst suspend configuration parameters comprises a first NCC value and afirst resume identity (ID). Based on receiving the first suspendconfiguration parameters, the UE may perform the suspending RRCconnection based on the first suspend configuration parameters. The UEmay transition to an RRC idle state or an RRC inactive state. Based onthe RRC release message, the UE may perform a cell (re)selectionprocedure. Based on the cell (re)selection procedure, the UE in an RRCidle state or an RRC inactive state may select a cell 2 of a second basestation (a target base station). The UE in an RRC idle state or an RRCinactive may have a first uplink data and a second uplink data in uplinkbuffer. The UE in an RRC idle state or an RRC inactive may have uplinkresource for a first UP small data transmission based on the EDT RACH orthe PUR configuration parameters where the uplink resource for a firstUP small data transmission comprises at least one of the uplink resourcefor EDT or the (preconfigured) uplink resource for PUR. The UE in an RRCidle state or an RRC inactive may not send both of the first uplink dataand the second uplink data via (or during) a first UP small datatransmission using the uplink resource for a first UP small datatransmission. For example, the UE in an RRC idle state or an RRCinactive may send the first uplink data via (or during) the first UPsmall data transmission using the uplink resource for a first UP smalldata transmission but not send both of the first uplink data and thesecond uplink data using the uplink resource for a first UP small datatransmission. The UE in an RRC idle state or an RRC inactive state maydetermine to perform the initiating UP small data transmission for thefirst UP small data transmission. In response to the initiating UP smalldata transmission for the first UP small data transmission, the UE in anRRC idle state or an RRC inactive may perform the sending small data forthe first UP small data transmission using the suspend configurationparameters. For example, the UE in an RRC idle state or an RRC inactivemay send (e.g., in 1^(st) Msg 3) at least one of the first uplink data,the RRC resume request message and BSR requesting uplink resource forthe second uplink data, using the uplink resource for a first UP smalldata transmission. The UE in an RRC idle state or an RRC inactive mayreceive a first response message (e.g., in Msg 4) in response to thefirst uplink data, the RRC resume request message and/or the BSR. Thefirst response message may comprise downlink data, uplink resource forthe second uplink data, acknowledgment for the first uplink data. Basedon the first response message, the UE in an RRC idle state or an RRCinactive may consider the first UP small data transmission beingsuccessful. Based on the considering, the UE in an RRC idle state or anRRC inactive may empty at least one of uplink buffer for the firstuplink data and/or uplink buffer for the RRC resume request message. Forexample, based on the considering, the UE in an RRC idle state or an RRCinactive may flush at least one of HARQ buffer for the first uplink dataand/or HARQ buffer for the RRC resume request message. A base stationmay allow the UE in an RRC idle state or an RRC inactive to performsubsequent transmission without the transitioning to an RRC connectedstate after the considering the first UP small data transmission beingsuccessful where the base station may be the first base station or thesecond base station. Based on the subsequent transmission allowinformation, the UE in an RRC idle state or an RRC inactive may performsending subsequent data (e.g., the second uplink data) using the uplinkresource for the second uplink data without transitioning to an RRCconnected state. The first response message (e.g., in Msg 4) maycomprise an RRC release message comprising a second suspendconfiguration parameters. Based on the RRC release message comprisingthe second suspend configuration parameters, the UE in an RRC idle stateor an RRC inactive may perform the suspending RRC connection based onthe second suspend configuration parameters. In response to thesuspending RRC connection, the UE in an RRC idle state or an RRCinactive may perform a second UP small data transmission (e.g., in Msg 5or Msg 6) based on the second suspend configuration parameters. The UEin an RRC idle state or an RRC inactive may need a third suspendconfiguration parameters for next UP small data transmission (e.g., athird UP small data transmission) before the second UP small datatransmission being successful. The UE in an RRC idle state or an RRCinactive may receive a second response message (e.g., in Msg 6) for thesecond uplink data. The second response message may comprise at leastone of acknowledgment for the second uplink data, downlink data and anRRC release message comprising the third suspend configurationparameters. Based on receiving the second response message, the UE in anRRC idle state or an RRC inactive may empty uplink buffer for the seconduplink data. Based on receiving the third suspend configurationparameters, the UE in an RRC idle state or an RRC inactive may performsuspending RRC connection. The UE in an RRC idle state or an RRCinactive may have a third uplink data. The UE in an RRC idle state or anRRC inactive may perform a third small data transmission (e.g., in2^(nd) Msg 3) based on the third suspend configuration parameters. TheRRC release message comprising the third suspend configurationparameters may be burden for a base station and a UE.

Example embodiments of the present disclosure are directed to a supportfor subsequent data transmission. Whereas existing technologies continueto have latency and signaling overheads for consecutive small datatransmissions, example embodiments support consecutive small datatransmissions without transitioning to an RRC connected state (e.g.,subsequent transmission) by delaying UE actions for an RRC releasemessage and allowing a UE to transmit and receive small data based onprevious/existing (suspend) configuration parameters.

In an example, a UE in an RRC idle state or an RRC inactive state maysend at least one of an RRC request message and/or a first uplink data.In response to at least one of the RRC request message and/or the firstuplink data, the UE in an RRC idle state or an RRC inactive state mayreceive a first response message comprising an RRC response messagerequesting to release or suspend an RRC connection. The UE in an RRCidle state or an RRC inactive state may determine to perform subsequenttransmission. Based on the determining, the UE may delay UE actions forthe RRC response message requesting to release or suspend an RRCconnection. Based on the determining, the UE in an RRC idle state or anRRC inactive state may send small data to a base station or receivesmall data from the base station without transitioning to the RRCconnected state (e.g., while staying in an RRC idle state or an RRCinactive state). Based on completion of the subsequent transmission, theUE may perform the delayed UE actions for the RRC response message.

In an example, the UE actions for the RRC response message may be the UEactions for the RRC release message. For example, the UE actions for theRRC response message may comprise at least one of:

-   -   discarding uplink data in uplink buffer;    -   discarding uplink resource; and/or    -   performing cell (re)selection procedure.

In an example, an RRC release message (e.g., the first response messageor the second RRC message) may comprise a delay indication. For example,a base station may send the RRC release message comprising the delayindication to a UE. Based on the delay indication, the UE may delay UEactions for the RRC response message (e.g., requesting to release orsuspend an RRC connection). Based on completion of the subsequenttransmission, the UE may perform the delayed UE actions for the RRCresponse message.

In an example, the delay indication may be applied per eachconfiguration parameters of the RRC response message or each UE actionfor the RRC response message. For example, the RRC response message maycomprise at least one of:

-   -   a delay indication for suspend configuration parameters;    -   a delay indication for releasing RRC connection;    -   a delay indication for cell (re)selection information;    -   a delay indication for idle/inactive measurements;    -   a delay indication for discarding uplink data in uplink buffer        and/or uplink resource for uplink data; or    -   a delay indication for one configuration parameters.

For example, based on the delay indication for suspend configurationparameters, the UE may delay the suspending RRC connection based on thesuspend configuration parameters. Based on the delay indication forreleasing RRC connection, the UE may delay the releasing RRC connection(e.g., based on the RRC response message or the RRC release message).Based on the delay indication for cell (re)selection information, the UEmay delay the cell (re)selection information. Based on the delayindication for idle/inactive measurements, the UE may delay theidle/inactive measurements. Based on the delay indication for discardinguplink data in uplink buffer and uplink resource for uplink data, the UEmay delay the discarding uplink data in uplink buffer and uplinkresource for uplink data. Based on a delay indication for oneconfiguration parameters, the UE may delay applying the oneconfiguration parameters. Based on completion of the subsequenttransmission, the UE may perform the delayed UE actions for the RRCresponse message.

In an example, an RRC release message (e.g., the first response messageor the second RRC message) may comprise a immediate indication. Forexample, a base station may send the RRC release message comprising theimmediate indication to a UE. Based on the immediate indication, the UEmay perform UE actions for the RRC response message (e.g., requesting torelease or suspend an RRC connection). The performing the UE actions forthe RRC release message may comprise delaying the UE actions for the RRCrelease message a period of time (e.g., 60 ms) from the moment the RRCrelease message was received or when the receipt of the RRC releasemessage was successfully acknowledged. For example, the performing theUE actions for the RRC release message may comprise performing the UEactions for the RRC release message after a period of time (e.g., 60 ms)from the moment the RRC release message was received or after when thereceipt of the RRC release message was successfully acknowledged.

In an example, the delay indication may be applied per eachconfiguration parameters of the RRC response message or each UE actionfor the RRC response message. For example, the RRC response message maycomprise at least one of:

-   -   an immediate indication for suspend configuration parameters;    -   an immediate indication for releasing RRC connection;    -   an immediate indication for cell (re)selection information;    -   an immediate indication for idle/inactive measurements;    -   an immediate indication for discarding uplink data in uplink        buffer and/or uplink resource for uplink data; or    -   an immediate indication for one configuration parameters.

For example, based on the immediate indication for suspend configurationparameters, the UE may perform the suspending RRC connection based onthe suspend configuration parameters. Based on the immediate indicationfor releasing RRC connection, the UE may perform the releasing RRCconnection (e.g., based on the RRC response message or the RRC releasemessage). Based on the immediate indication for cell (re)selectioninformation, the UE may perform the cell (re)selection information.Based on the immediate indication for idle/inactive measurements, the UEmay perform the idle/inactive measurements. Based on the immediateindication for discarding uplink data in uplink buffer and uplinkresource for uplink data, the UE may perform the discarding uplink datain uplink buffer and uplink resource for uplink data. Based on animmediate indication for one configuration parameters, the UE mayperform to apply the one configuration parameters. The performing one ofUE actions may comprise delaying the UE action a period of time (e.g.,60 ms) from the moment the RRC release message was received or when thereceipt of the RRC release message was successfully acknowledged. Forexample, the performing one of UE actions may comprise performing the UEactions for the RRC release message after a period of time (e.g., 60 ms)from the moment the RRC release message was received or after when thereceipt of the RRC release message was successfully acknowledged.

In an example, a UE in an RRC idle state or an RRC inactive state maysend at least one of an RRC request message and/or a first uplink data.In response to at least one of the RRC request message and/or the firstuplink data, the UE in an RRC idle state or an RRC inactive state mayreceive a first response message comprising an RRC response messagerequesting to release or suspend an RRC connection. The first responsemessage may further comprise a delay indication for the RRC responsemessage. Based on the delay indication, the UE may delay UE actions forthe RRC response message requesting to release or suspend an RRCconnection. The UE in an RRC idle state or an RRC inactive state maydetermine to perform subsequent transmission. Based on the determining,the UE in an RRC idle state or an RRC inactive state may send small datato a base station or receive small data from the base station withouttransitioning to the RRC connected state (e.g., while staying in an RRCidle state or an RRC inactive state). Based on completion of thesubsequent transmission, the UE may perform the delayed UE actions forthe RRC response message. In an example, the delay indication may beapplied per each configuration parameters of the RRC response message oreach UE action for the RRC response message. For example, the RRCresponse message may comprise at least one of:

-   -   a delay indication for suspend configuration parameters;    -   a delay indication for releasing RRC connection;    -   a delay indication for cell (re)selection information;    -   a delay indication for idle/inactive measurements; or    -   a delay indication for discarding uplink data in uplink buffer        and/or uplink resource for uplink data.

For example, based on the delay indication for suspend configurationparameters, the UE may delay the suspending RRC connection based on thesuspend configuration parameters. Based on the delay indication forreleasing RRC connection, the UE may delay the releasing RRC connection(e.g., based on the RRC response message or the RRC release message).Based on the delay indication for cell (re)selection information, the UEmay delay the cell (re)selection information. Based on the delayindication for idle/inactive measurements, the UE may delay theidle/inactive measurements. Based on the delay indication for discardinguplink data in uplink buffer and uplink resource for uplink data, the UEmay delay the discarding uplink data in uplink buffer and uplinkresource for uplink data.

In an example, the UE may determine the completion of the subsequenttransmission based on at least one of:

-   -   receiving a last response message for subsequent transmission;        or    -   receiving a response message for subsequent transmission being        failed.

The last response message for subsequent transmission may comprise atleast one of:

-   -   acknowledgement for the last uplink data;    -   last downlink data;    -   an indication to complete subsequent transmission; or    -   fall back indication;

The performing the subsequent transmission may comprise at least one ofsending one or more uplink data to a base station and/or receiving oneor more downlink data from the base station during the subsequenttransmission (period) where the base station may be the first basestation or the second base station. During the subsequent transmission,the UE may one or more uplink data (or uplink signaling). The UE maysends each uplink data in each uplink timing (e.g., Msg 5 timing or Msg7 timing, etc.). The UE may sends the last uplink data of uplink bufferin last uplink timing. Based on the sending the last uplink data beingsuccessful, the UE does not have remaining of the uplink buffer to send.For example, based on the subsequent transmission comprising at leastone of one uplink data or one downlink data, the last uplink data may bethe one uplink data of subsequent transmission and the last downlinkdata may be the one downlink data of subsequent data transmission. Forexample, a first response message in response to at least one of the RRCrequest message and/or the first uplink data may comprise expectednumber of uplink data transmission and/or downlink data transmissionduring subsequent transmission. Based on the expected number, the UE maydetermine the last uplink data and/or the last downlink data. Forexample, the completion of the subsequent transmission may be completionof sending second uplink data based on the last uplink data being thesecond uplink data.

In an example, a base station or a core network entity (e.g., AMF, SMFor UPF) may send a signalling/data to a UE. The base station may need aresponse signalling/data for the signalling to make sure whether the UEsuccessfully receive it and/or accept it. The base station or the AMFmay send the signalling/data via the first response message in a smalldata transmission where the first response message may comprise thesignalling/data. For example, the signalling/data may comprise at leastone of AS signalling/data (e.g., an downlink RRC message or MAC CE) orNAS signalling/data (e.g., an downlink NAS message). For example, theAMF or the SMF may send the NAS signalling/data to the UE via the basestation. Based on receiving the NAS signalling/data, the base stationmay send an RRC message comprising the NAS signalling/data to the UE.For example, the base station may send a AS signalling/data (e.g., thedownlink RRC message or MAC CE). For example, the base station or thecore network entity may send the first response message comprising atleast one of the signalling/data and an indication for further uplinksignalling/data being expected. For example, an indication may be oneuplink signalling/data being expected.

Based on the indication, the UE in an RRC idle state or an RRC inactivestate may perform subsequent transmission without transitioning to theRRC connected state (e.g., while staying in an RRC idle state or an RRCinactive state). Based on the performing the subsequent transmission,the UE may send the response signalling/message to the base station orthe core network entity. For example, based on the indication, the UE inan RRC idle state or an RRC inactive state may determine to performsubsequent transmission. Based on the determining, the UE in an RRC idlestate or an RRC inactive state may send the response signalling/data tothe base station or the core network entity. For example, in response tothe AS signalling/data from the base station, the UE may send a ASresponse signalling/data (e.g., an RRC message or MAC CE) to the basestation. For example, in response to the NAS signalling/data, the UE maysend a NAS response signalling/data to the core network entity (e.g.,the AMF or the SMF) via the base station. For example, based on thesending send a NAS response signalling/data, the UE may send an uplinkRRC message comprising the NAS response signalling/data to the basestation. Based on receiving the uplink RRC message, the base station mayforward the NAS response signalling/data to the core network entity andsend acknowledgment for the uplink RRC message to the UE. Based onsuccessfully sending the response signalling/data, the UE may performthe (delayed) UE actions for RRC release message. The UE may determinethe successfully sending the response signalling/data based on receivingacknowledgement (e.g. HARQ ack or RLC ack) for the responsesignalling/data.

In an example embodiment, the UE may determine the receiving a responsemessage in response to subsequent transmission being failed based on asubsequent timer being expired. For example, The subsequent timer may bedownlink monitoring window timer for downlink data or signaling responseto uplink transmission of the subsequent transmission (e.g., PURresponse window timer). The UE may receive the subsequent timer from abase station by dedicated signaling or broadcasted signaling (e.g.,system information). For example, the UE may receive the subsequenttimer via the first response message (e.g., Msg 4).

In an example, the UE may start the subsequent timer to monitor orsupervise uplink data transmission of subsequent transmission based onsending the uplink data or signaling for the uplink transmission. The UEmay stop the subsequent timer based on receiving a response message forthe uplink data when the subsequent timer is running. The subsequenttimer may be expired. For example, based on not receiving the responsemessage, the subsequent timer may be expired. The subsequenttransmission may comprise one or more small data transmissions. Forexample, the subsequent transmission may comprise one or more uplinktransmission occasions. The UE may determine amount of uplink data orsignaling at each uplink data transmission occasion based on uplinkresource (or uplink grant). The UE may send the uplink data or signalingat the each uplink transmission occasion. For example, the UE may sendone MAC PDU comprising the uplink data or signaling using the uplinkresource (or uplink grant) at the each uplink transmission occasion. TheUE may (re)start the subsequent timer based on the sending the uplinkdata or signaling at the each uplink data transmission occasion. Basedon receiving a response message in response to the uplink data orsignaling, the UE may stop the subsequent timer. Based on not receivingthe response message, the subsequent timer may be expired.

In an example, the subsequent timer may be a inactivity timer ofsubsequent transmission. A UE may start the subsequent timer based onreceiving the first response message (e.g., in Msg 4). For example, thefirst response message may comprise the subsequent timer. Based onreceiving the first response message comprising the subsequent timer,the UE may start the subsequent timer. The UE may (re)start thesubsequent timer based on receiving downlink signaling or data from abase station, or transmitting uplink signaling or data to the basestation if the subsequent timer is running.

In an example, a base station (e.g., the first base station or thesecond base station) may send the subsequent timer to a UE. For example,the second base station may send the subsequent timer via the firstresponse message. Based on receiving the subsequent timer, the UE mayuse the subsequent timer. The UE may store the subsequent timer. Thebase station may store the subsequent timer in UE context of the UE. Forexample, the UE may store the subsequent timer in UE inactive AScontext. The base station may store the subsequent timer of the UE inthe UE inactive AS context. The UE may restore the subsequent timerbased on at least one of initiating RRC connection resume procedure(e.g., initiating small data transmission) or determining/initiating toperform subsequent transmission. The base station may restore thesubsequent timer in the US inactive AS context based on at least one ofreceiving an RRC resume request message for the RRC connection resumeprocedure or determining/initiating to perform subsequent transmission.

In an example, the UE may start a downlink monitoring window timer fordownlink data (or signaling) of the subsequent transmission based onreceiving a downlink message indicating PDCCH transmission. The UE maystop the downlink monitoring window timer based on receiving thedownlink data when the downlink monitoring window timer is running. Forexample, based on not receiving the downlink data, the downlinkmonitoring window timer may be expired. The downlink monitoring windowtimer may be PUR response window timer. For example, the UE may startthe PUR response window timer based on sending at least one of an RRCrequest message and/or a first uplink data. The UE may a first responsemessage in response to at least one of an RRC request message and/or afirst uplink data. The first response message may comprise the downlinkmessage. The UE may receive one or more downlink data during thesubsequent transmission. The UE may (re)start a downlink monitoringwindow timer based on receiving each downlink message indicating PDCCHtransmission. The UE may stop the downlink monitoring window timer basedon receiving each downlink data associated to the each downlink messagewhen the downlink monitoring window timer is running. For example, basedon not receiving the each downlink data, the downlink monitoring windowtimer may be expired.

FIG. 31 illustrates an example diagram of consecutive small datatransmissions based on subsequent transmission with receiving RRCrelease message. The UE in an RRC idle state or an RRC inactive statemay send at least one of an RRC request message and/or a first uplinkdata. In response to at least one of the RRC request message and/or thefirst uplink data, the UE in an RRC idle state or an RRC inactive statemay receive an RRC response message requesting to release or suspend anRRC connection. Based on determining to perform subsequent transmissionor the delay indication, the UE in an RRC idle state or an RRC inactivestate may delay one or more UE actions for the RRC response message.Based on completion of the subsequent transmission, the UE in an RRCidle state or an RRC inactive state may perform the one or more UEactions for the RRC response message.

In an example, a UE in an RRC connected state may communicate with afirst base station based on first configuration parameters and firstsecurity keys. The first base station may send an RRC release message tothe UE. Based on the RRC release message, the UE may transition to anRRC idle state or an RRC inactive state. The UE in an RRC idle state oran RRC inactive state may send at least one of an RRC request messageand/or a first uplink data. In response to at least one of the RRCrequest message and/or the first uplink data, the UE in an RRC idlestate or an RRC inactive state may receive a first response message. Thefirst response message may comprise an RRC response message requestingto release or suspend an RRC connection. Based on at least one of thedetermining subsequent transmission or the delay indication, the UE inan RRC idle state or an RRC inactive state may delay one or more UEactions for the RRC response message. Based on completion of thesubsequent transmission, the UE in an RRC idle state or an RRC inactivestate may perform the one or more UE actions for the RRC responsemessage.

FIG. 32 illustrates an example diagram of consecutive UP small datatransmissions based on subsequent transmission with receiving RRCrelease message comprising suspend configuration parameters. A UE mayreceive, from a first base station, a first RRC message comprising afirst suspend configuration parameters. The UE may send, based on thefirst suspend configuration parameters, at least one of a first uplinkdata and a second RRC message requesting to resume an RRC connection.The UE may receive, in response to the second RRC message, a third RRCmessage comprising a second suspend configuration parameters. The UE maysend, after the receiving the third message, second uplink data usingthe first suspend configuration parameters. The UE may send, based oncompletion of the subsequent transmission (e.g., completion of thesending the second uplink data), at least one of third uplink dataand/or a fourth RRC message requesting to resume the RRC connection,using the second suspend configuration parameters.

In an example embodiment, a UE may receive, from a first base station, afirst RRC message comprising a first suspend configuration parameters.The UE may send, based on the first suspend configuration parameters, atleast one of a first uplink data and a second RRC message requesting toresume an RRC connection. The UE may receive, in response to the secondRRC message, a third RRC message comprising a second suspendconfiguration parameters. The UE may communicate, after the receivingthe third message, with a base station using the first suspendconfiguration parameters. The UE may send, based on completion of thesubsequent transmission (e.g., completion of the sending the seconduplink data), at least one of third uplink data and/or a fourth RRCmessage requesting to resume the RRC connection, using the secondsuspend configuration parameters. For example, the communicating maycomprise sending one or more uplink signaling/data and receiving one ormore downlink signaling/data.

In an example, a UE may receive, from a first base station, a first RRCmessage comprising a first suspend configuration parameters. The UE maysend, based on the first suspend configuration parameters, at least oneof a first uplink data and a second RRC message requesting to resume anRRC connection. The UE may receive, in response to the second RRCmessage, a third RRC message requesting to release an RRC connection.The UE may communicate, after the receiving the third message, with abase station using the first suspend configuration parameters. The UEmay perform, based on completion of the subsequent transmission (e.g.,completion of the sending the second uplink data), the releasing the RRCconnection based on the third RRC message.

In an example, a UE may receive, from a first base station, a first RRCmessage requesting to release an RRC connection. Based on the first RRCmessage, the UE may transition to an RRC idle state. The UE in an RRCidle state may send CP small data via control plane. For example, the UEin an RRC idle state may send at least one of a second RRC message and afirst uplink data via control plane. The UE may receive, in response tothe second RRC message, a third RRC message comprising a suspendconfiguration parameters. The UE may communicate, after the receivingthe third message, via control plane with a base station. The UE maysend, based on completion of the subsequent transmission (e.g.,completion of the sending the second uplink data), at least one of thirduplink data and/or a fourth RRC message requesting to resume the RRCconnection, using the suspend configuration parameters.

In an example, the communicating with the base station using the firstsuspend configuration parameters may comprise at least one of sendingone or more uplink small data to the base station or receiving one ormore downlink small data from the base station, using the derivedsecurity keys (e.g., second security keys) and the restoredconfiguration parameters (e.g., the first configuration parameters)based on the first suspend configuration parameters. For example, The UEmay derive the second security keys and restore the stored configurationparameters based on the first configuration parameters. Based on thesecond security keys and the restored configuration parameters, the UEmay send at least one of the first uplink data and/or the second RRCmessage (e.g., the RRC request message) and/or receive (a first responsemessage comprising) the third RRC message. The UE may send one or moreuplink small data to the base station and/or receive one or moredownlink small data from the base station, using the second securitykeys and the restored configuration parameters (e.g., the firstconfiguration parameters) during the subsequent transmission (e.g.,before the completion of subsequent transmission). The base station maybe the first base station or a second base station.

In an example, the sending one or more uplink small data using thesecond security keys and the restored configuration parameters maycomprise at least one of:

-   -   performing ciphering and/or integrity protection with the one or        more uplink small data based on the second security keys; and/or    -   sending the one or more uplink small data based on the restored        configuration parameters.

For example, the sending the one or more uplink small data based on therestored configuration parameters may comprise at least one of:

-   -   performing header compression of the one or more uplink small        data based on the ROHC states (e.g., PDCP configuration        parameters) of the restored configuration parameters; or    -   sending the one or more uplink small data based on QoS flow to        DRB mapping rules of one or more bearers associated to the one        or more uplink data.

In an example, the receiving (a first response message comprising) thethird RRC message based on the second security keys and the restoredconfiguration parameters may comprise at least one of:

-   -   performing deciphering and/or integrity protection verification        with the third RRC message based on the second security keys;        and/or    -   receiving the third RRC message based on the first stored        configuration parameters.    -   The receiving one or more downlink small data using the second        security keys and the restored configuration parameters may        comprise at least one of:    -   performing deciphering and/or integrity protection verification        with the one or more downlink small data based on the second        security keys; and/or    -   receiving the one or more downlink small data based on based on        QoS flow to DRB mapping rules of one or more bearers associated        to the one or more downlink data.

In an example, the one or more uplink small data may comprise the seconduplink data. The one or more downlink small data may comprise thedownlink data received during the subsequent transmission. For example,the second response message may comprise the downlink data.

FIG. 33 illustrates an example of consecutive UP small datatransmissions based on subsequent transmission with receiving RRCrelease message comprising suspend configuration parameters. A UE in anRRC connected state may communicate with a first base station based onfirst configuration parameters and first security keys. The first basestation may send an RRC release message comprising first suspendconfiguration parameters where the first suspend configurationparameters comprises a first NCC value and a first resume identity (ID).Based on receiving the first suspend configuration parameters, the UEmay perform the suspending RRC connection based on the first suspendconfiguration parameters. Based on the suspending RRC connection, the UEmay transition to an RRC idle state or an RRC inactive state. The UE mayreceive PUR configuration parameters via previous RRC release message.The previous RRC release message may be the RRC release message. The UEin an RRC idle state or an RRC inactive may have a first uplink data anda second uplink data in uplink buffer. The UE in an RRC idle state or anRRC inactive state may determine to perform the initiating UP small datatransmission for a first small data transmission based on the UP EDTconditions or the UP PUR conditions being met. Based on the determining,the UE may perform the initiating UP small data transmission for thefirst small data transmission based on the first suspend configurationparameters. The UE may have uplink resource for small data transmissionbased on the EDT RACH or the PUR configuration parameters where theuplink resource for small data transmission comprise at least one of theuplink resource for EDT or the (preconfigured) uplink resource for PUR.In response to the initiating UP small data transmission for the firstsmall data transmission, the UE in an RRC idle state or an RRC inactivemay perform the sending UP small data for the first small datatransmission using the first suspend configuration parameters. Forexample, the UE may send (e.g., in 1^(st) Msg 3) at least one of thefirst uplink data, the RRC resume request message and BSR requestinguplink resource for the second uplink data in uplink buffer, using theuplink resource for small data transmission. The UE may receive a firstresponse message (e.g., in Msg 4) in response to at least one of thefirst uplink data and/or the RRC resume request message. The firstresponse message may comprise at least one of a downlink message, an RRCrelease message, uplink resource for the second uplink data and/ordownlink data. For example, the RRC release message may comprise secondsuspend configuration parameters comprising a second NCC value and asecond resume identity (ID). Based on receiving the first responsemessage, the UE in an RRC idle state or an RRC inactive may consider UPsmall data transmission for the first small data transmission beingsuccessful. Based on the considering, the UE in an RRC idle state or anRRC inactive may empty at least one of uplink buffer for the firstuplink data and/or uplink buffer for the RRC resume request message. Forexample, in response to the 1^(st) Msg 3 comprising at least one of thefirst uplink data and/or the RRC resume request message, the UE in anRRC idle state or an RRC inactive may receive Msg 4. The Msg 4 maycomprise at least one of the downlink message, the RRC release messageand/or downlink data. Based on receiving the Msg 4, the UE in an RRCidle state or an RRC inactive may consider the UP small datatransmission via Msg 3 being successful. Based on the considering, theUE in an RRC idle state or an RRC inactive may empty at least one ofuplink buffer for the first uplink data and/or uplink buffer for the RRCresume request message. For example, based on the considering, the UE inan RRC idle state or an RRC inactive may flush at least one of HARQbuffer for the first uplink data and/or HARQ buffer for the RRC resumerequest message. In response to the first response message, the UE in anRRC idle state or an RRC inactive state may send the second uplink data(e.g., in Msg 5) and/or receive a second response message (e.g., in Msg6) in response to the second uplink data, using the first suspendconfiguration parameters. For example, the second response message maycomprise at least one of acknowledgment for the second uplink dataand/or downlink data. Based on receiving the second response message,the UE may consider the subsequent transmission (e.g., the sending thesecond uplink data) successful. Based on the considering, the UE in anRRC idle state or an RRC inactive state may empty uplink buffer for thesecond uplink data. Based on the completion of the subsequenttransmission (e.g., the sending the second uplink data), the UE in anRRC idle state or an RRC inactive state may perform the suspending RRCconnection based on the second suspend configuration parameters. Thesuspending RRC connection based on the second configuration parametersmay comprise that the UE performs at least one of:

-   -   discarding uplink data in uplink buffer;    -   storing the first configuration parameters and the second        security keys;    -   suspending bearers except for SRB0; and/or    -   transitioning to an RRC idle state or an RRC inactive state.

Based on the suspending RRC connection, the UE in an RRC idle state oran RRC inactive state may transition to an RRC idle state or an RRCinactive state. The UE in an RRC idle state or an RRC inactive state mayhave third uplink data. The UE in an RRC idle state or an RRC inactivestate may perform initiating UP small data transmission (e.g., secondsmall data transmission). the initiating UP small data transmissionusing the second suspend configuration parameters may comprise that theUE perform at least one of:

-   -   restoring the first configuration parameters and the second        security keys;    -   deriving a second resume MAC-I based on the second security        keys;    -   deriving third security keys based on the second security keys        and the second NCC value; and    -   resuming all suspended bearers.

In response to the initiating UP small data transmission using thesecond suspend configuration parameters, the UE may perform sending UPsmall data (e.g., 2nd Msg 3) using the second suspend configurationparameters. For example, the sending UP small data using the secondsuspend configuration parameters may comprise that the UE perform atleast one of:

-   -   generating an RRC resume request message by setting the contents        of the RRC resume request message where the RRC resume request        message comprises the second resume identity and the second        resume MAC-I;    -   performing ciphering and/or integrity protection with the third        uplink data based on the third security keys; and/or    -   sending at least one of the RRC resume request message and/or        the third uplink data based on the first configuration        parameters.

In an example embodiment, the first response message (e.g., in Msg 4)may further comprise subsequent configuration parameters. The subsequentconfiguration parameters may be used to configure a UE in an RRC idlestate or an RRC inactive state with serving cell configurationparameters for subsequent transmission. The serving cell configurationparameters may be mostly UE specific but partially also cell specific.The (second) base station may send the subsequent configurationparameters via the first response message. For example, the third RRCmessage (e.g., the RRC release message of the first response message)may comprise the subsequent configuration parameters. In response toreceiving the subsequent configuration parameters, the UE in an RRC idlestate or an RRC inactive state may perform the subsequent transmissionbased on the subsequent configuration parameters. For example, the UE inan RRC idle state or an RRC inactive state may perform the first (UP)small data transmission using the first suspend configurationparameters. In response to receiving the subsequent configurationparameters, the UE in an RRC idle state or an RRC inactive state mayperform the subsequent transmission based on the subsequentconfiguration parameters and the first suspend configuration parameters.

In an example, an RRC release message (e.g., the first response messageor the second RRC message) may comprise a immediate indication for thesubsequent configuration parameters. For example, a base station maysend the RRC release message comprising the immediate indication for thesubsequent configuration parameters to a UE. Based on the immediateindication for the subsequent configuration parameters, the UE mayperform to apply/configure the subsequent configuration parameters. Forexample, based on the immediate indication for the subsequentconfiguration parameters, the UE may perform the subsequent transmissionusing the subsequent configuration parameters. The performing toapply/configure the subsequent configuration parameters may comprisedelaying to apply/configure the subsequent configuration parameters aperiod of time (e.g., 60 ms) from the moment the RRC release message(e.g., the subsequent configuration parameters) was received or when thereceipt of the RRC release message (e.g., the subsequent configurationparameters) was successfully acknowledged. For example, the performingto apply/configure the subsequent configuration parameters may compriseperforming to apply/configure the subsequent configuration parametersafter a period of time (e.g., 60 ms) from the moment the RRC releasemessage was received or after when the receipt of the RRC releasemessage was successfully acknowledged.

In an example, the subsequent configuration parameters may comprise atleast one of radio bearer configuration parameters and/or cell groupconfiguration parameters. The cell group may comprise at least a firstcell of the second base station where the first cell is PCell andserving cell of the UE. For example, the radio bearer configurationparameters may comprise signaling radio bearer configuration parameters.For example, based on UP small data transmission, the radio bearerconfiguration parameters may signaling radio bearer configurationparameters. Based on the radio bearer configuration parameters, the UEin an RRC idle or inactive state may (re)establish signaling radiobearers. The cell group configuration parameters may comprise at leastone of RLC bearer configuration parameters, MAC cell group configurationparameters, physical cell group configuration parameters, SpCellconfiguration parameters for the first cell group or SCell configurationparameters for other cells of the second base station. The SpCellconfiguration parameter may comprise at least one of radio link failuretimer and constraints, radio link monitoring in sync out of syncthreshold, and/or serving cell configuration parameters of the firstcell. The serving cell configuration parameters may comprise at leastone of:

-   -   downlink BWP configuration parameters;    -   uplink configuration parameters;    -   uplink configuration parameters for supplement uplink carrier        (SUL);    -   PDCCH parameters applicable across for all BWPs of a serving        cell;    -   PDSCH parameters applicable across for all BWPs of a serving        cell;    -   CSI measurement configuration parameters;    -   SCell deactivation timer;    -   cross carrier scheduling configuration parameters for a serving        cell;    -   timing advance group (TAG) identity (ID) of a serving cell;    -   path loss reference linking indicating whether the UE shall        apply as pathloss reference either the downlink of SpCell or        SCell for this uplink;    -   serving cell measurement configuration parameters;    -   channel access configuration parameters for access procedures of        operation with shared spectrum channel access;

The CSI measurement configuration parameters may be to configure CSI-RS(reference signals) belonging to the serving cell, channel stateinformation report to configure CSI-RS (reference signals) belonging tothe serving cell and channel state information reports on PUSCHtriggered by DCI received on the serving cell.

In an example, the downlink BWP configuration parameters may be used toconfigure dedicated (UE specific) parameters of one or more downlinkBWPs. The one or more downlink BWPs may comprise at least one of aninitial downlink BWP, a default downlink BWP and a first active downlinkBWP. The downlink BWP configuration parameters may comprise at least oneof:

-   -   configuration parameters for the one or more downlink BWPs;    -   one or more downlink BWP IDs for the one or more downlink BWPs;    -   BWP inactivity timer;

The configuration parameters for a downlink BWP may comprise at leastone of:

-   -   PDCCH configuration parameters for the downlink BWP;    -   PDSCH configuration parameters for the downlink BWP;    -   semi-persistent scheduling (SPS) configuration parameters for        the downlink BWP;    -   beam failure recovery SCell configuration parameters of        candidate RS; and/or    -   radio link monitoring configuration parameters for detecting        cell- and beam radio link failure occasions for the downlink        BWP;

The one or more downlink BWP IDs may comprise at least one of an initialdownlink BWP ID, a default downlink BWP identity (ID) and a first activedownlink BWP ID.

In an example, the uplink configuration parameters may be uplinkconfiguration parameters for normal uplink carrier (not supplementaryuplink carrier). The uplink configuration parameters (or the uplinkconfiguration parameters for SUL) may be used to configure dedicated (UEspecific) parameters of one or more uplink BWPs. The one or more uplinkBWPs may comprise at least one of an initial uplink BWP and a firstactive uplink BWP. The uplink BWP configuration parameters may compriseat least one of:

-   -   configuration parameters for the one or more uplink BWPs;    -   one or more uplink BWP IDs for the one or more uplink BWPs;    -   PUSCH parameters common across the UE's BWPs of a serving cell;    -   SRS carrier switching information;    -   power control configuration parameters;

The configuration parameters for a uplink BWP may comprise at least oneof:

-   -   one or more PUCCH configuration parameters for the uplink BWP;    -   PUSCH configuration parameters for the uplink BWP;    -   one or more configured grant configuration parameters for the        uplink BWP;    -   SRS configuration parameters for the uplink BWP;    -   beam failure recovery configuration parameters for the uplink        BWP; and/or    -   cyclic prefix (CP) extension parameters for the uplink BWP.

The one or more uplink BWP IDs may comprise at least one of an initialuplink BWP ID (e.g., the initial uplink BWP ID=0) and/or an first activeuplink BWP ID. The SRS carrier switching information may be is used toconfigure for SRS carrier switching when PUSCH is not configured andindependent SRS power control from that of PUSCH. The power controlconfiguration parameters may comprise at least one of power controlconfiguration parameters for PUSCH, power configuration controlparameters for PUCCH and power control parameters for SRS.

In an example, the subsequent configuration parameters may furthercomprise at least one of:

-   -   PDCP configuration for one or more bearers;    -   QoS flow to DRB mapping rules for one or more bearers;    -   C-RNTI used in source PCell; and    -   cell identity and physical cell identity of source PCell;

In an example, the subsequent configuration parameters may have sameparameters with the first configuration parameters. Based on thesubsequent configuration parameters having same parameters with thefirst configuration parameters, the UE may replace the same parametersof the subsequent configuration parameters with the same parameters ofthe first configuration parameters. For example, the subsequentconfiguration parameters may comprise the PDCP configuration parametersfor one or more bearers. The UE may update the PDCP configurationparameters of the first configuration parameters with the PDCPconfiguration parameters of the subsequent configuration parameters. TheUE may configure the updated PDCP configuration parameters. For example,the UE may discard some of the PDCP configuration parameters of thefirst configuration parameters based on the some of PDCP configurationparameters in the contents of the PDCP configuration parameters of thesubsequent configuration parameters, and may configure the some of PDCPconfiguration parameters of the subsequent configuration parameters. Forexample, based on the PDCP configuration parameters comprising headercompression parameters, the UE may discard the ROHC states of the firstconfiguration parameters. For example, based on the PDCP configurationparameters comprising header compression parameters, the UE mayconfigure the head compression parameters for the one or more bearers.For example, the subsequent configuration parameters may comprise theQoS flow to DRB mapping rules for one or more bearers. Based on the QoSflow to DRB mapping rules for one or more bearers, the UE mayupdate/configure QoS flow to DRB mapping rules for the one or morebearers.

In an example, the subsequent configuration parameters may furthercomprise new security parameters. For example, the new securityparameters may comprise at least one of sk counter, security algorithmsand/or a NCC value. For example, based on the new security parameters,the UE may discard current security keys (e.g., the second securitykeys). Based on the new security parameters, the UE may derive newsecurity keys and configure the new security keys. For example, the UEmay communicate with a base station using the new security keys. Forexample, the UE may communicate with a base station for the subsequenttransmission using the new security keys.

In an example, the UE in an RRC idle state or an RRC inactive state mayperform the first (UP) small data transmission using the first suspendconfiguration parameters. In response to receiving the subsequentconfiguration parameters, the UE in an RRC idle state or an RRC inactivestate may perform the subsequent transmission based on the subsequentconfiguration parameters and the first suspend configuration parameters.

In an example, based on the subsequent configuration parameters havingoverlapping parameters with the first configuration parameters, theoverlapping parameters of the subsequent configuration parameters mayoverwrite the overlapping parameters of the first configurationparameters.

In existing technologies, a wireless device may perform a small datatransmission (SDT) procedure while in an RRC non-connected state (e.g.,RRC inactive and/or RRC idle). Communications associated with the SDTprocedure may be based on a suspend configuration of the wirelessdevice. The suspend configuration may, for example, include one or moreparameters received from a base station. The SDT procedure may beassociated with transmission of first data and subsequent data (e.g.,second data, etc.). The SDT procedure may be completed based on thesuspend configuration (e.g., one or more parameters of the suspendconfiguration). The suspend configuration may be maintainedindefinitely. For example, the SDT procedure may commence based on thesuspend configuration and may proceed using the suspend configuration,even if the suspend configuration is sub-optimal for SDT transmission.For example, the wireless device may continue to use the sub-optimalconfiguration in order to complete the SDT transmission, thereby wastingresources. For example, the wireless device may struggle to complete theSDT procedure because the configuration is sub-optimal.

In embodiments of the present disclosure, a wireless device may receivea suspend configuration. The wireless device may transmit first dataassociated with a small data transmission (SDT) procedure while in anRRC non-connected state (e.g., RRC inactive and/or RRC idle). Thewireless device may receive a subsequent configuration. The wirelessdevice may transmit, based on the subsequent configuration, second dataassociated with the SDT procedure. Accordingly, the wireless device mayflexibly perform and/or complete the SDT procedure based on thesubsequent configuration.

FIG. 34 illustrates an example of subsequent transmission based onsubsequent configuration parameters. The UE may receive, from a firstbase station, a first RRC message requesting to release or suspend anRRC connection. The UE in an RRC idle state or an RRC inactive state maysend at least one of first uplink data and/or a second RRC messagerequesting to resume the RRC connection. The UE may receive a third RRCmessage comprising subsequent configuration parameters in response tothe second RRC message. The UE may perform the subsequent transmissionusing the subsequent configuration parameters after the receiving thethird message. The UE may release, after the receiving the thirdmessage, the subsequent configuration parameters based on completion ofthe subsequent transmission.

In an example, the performing the subsequent transmission may compriseat least one of sending one or more uplink data to a base station and/orreceiving one or more downlink data from the base station during thesubsequent transmission (period) (e.g., from the initiating of thesubsequent transmission to the completion of subsequent transmission)where the base station may be the first base station or the second basestation. The UE may perform the subsequent transmission using thesubsequent configuration parameters. For example, the UE may send uplinkdata.

FIG. 35 illustrates an example of subsequent transmission withconsecutive UP small data transmissions. A UE in an RRC connected statemay communicate with a first base station based on first configurationparameters and first security keys. The first base station may send anRRC release message comprising first suspend configuration parameterswhere the first suspend configuration parameters comprises a first NCCvalue and a first resume identity (ID). Based on receiving the firstsuspend configuration parameters, the UE may perform the suspending RRCconnection based on the first suspend configuration parameters. Based onthe suspending RRC connection, the UE may transition to an RRC idlestate or an RRC inactive state. The UE may receive PUR configurationparameters via the RRC release message or a previous RRC releasemessage. The previous RRC release message may be the RRC releasemessage. The UE in an RRC idle state or an RRC inactive may have a firstuplink data and a second uplink data in uplink buffer. The UE in an RRCidle state or an RRC inactive state may determine to perform theinitiating UP small data transmission for a first small datatransmission based on the UP EDT conditions or the UP PUR conditionsbeing met. Based on the determining, the UE may perform the initiatingUP small data transmission for the first small data transmission basedon the first suspend configuration parameters. The UE may have uplinkresource for small data transmission based on the EDT RACH or the PURconfiguration parameters where the uplink resource for small datatransmission comprise at least one of the uplink resource for EDT or the(preconfigured) uplink resource for PUR. In response to the initiatingUP small data transmission for the first small data transmission, the UEin an RRC idle state or an RRC inactive may perform the sending UP smalldata for the first small data transmission using the first suspendconfiguration parameters. For example, the UE may send (e.g., in 1^(st)Msg 3) at least one of the first uplink data, the RRC resume requestmessage and BSR requesting uplink resource for the second uplink data inuplink buffer, using the uplink resource for small data transmission.The UE may receive a first response message for at least one of thefirst uplink data and/or the RRC resume request message. The firstresponse message (e.g., Msg 4) may comprise at least one of a downlinkmessage, an RRC release message, uplink resource for the second uplinkdata and/or downlink data. For example, the RRC release message maycomprise second suspend configuration parameters comprising a second NCCvalue and a second resume identity (ID). Based on receiving the firstresponse message, the UE in an RRC idle state or an RRC inactive mayconsider UP small data transmission for the first small datatransmission being successful. Based on the considering, the UE in anRRC idle state or an RRC inactive may empty at least one of uplinkbuffer for the first uplink data and/or uplink buffer for the RRC resumerequest message. For example, in response to the 1^(st) Msg 3 comprisingat least one of the first uplink data and/or the RRC resume requestmessage, the UE in an RRC idle state or an RRC inactive may receive Msg4. The Msg 4 may comprise at least one of the downlink message, the RRCrelease message and/or downlink data. Based on receiving the Msg 4, theUE in an RRC idle state or an RRC inactive may consider the UP smalldata transmission via the 1^(st) Msg 3 being successful. Based on theconsidering, the UE in an RRC idle state or an RRC inactive may empty atleast one of uplink buffer for the first uplink data and/or uplinkbuffer for the RRC resume request message. For example, based on theconsidering, the UE in an RRC idle state or an RRC inactive may flush atleast one of HARQ buffer for the first uplink data and/or HARQ bufferfor the RRC resume request message.

In an example, the first response message (e.g., in Msg 4) may furthercomprise subsequent configuration parameters. In response to the firstresponse message, the UE in an RRC idle state or an RRC inactive statemay send the second uplink data (e.g., in Msg 5) and/or receive a secondresponse message (e.g., in Msg 6) in response to the second uplink data,using the first suspend configuration parameters and the subsequentconfiguration parameters. For example, in response to the first responsemessage, the UE in an RRC idle state or an RRC inactive state may sendthe second uplink data and/or receive a second response message for thesecond uplink data, using the second security keys, the firstconfiguration parameters and the subsequent configuration parameters.For example, the second response message may comprise at least one ofacknowledgment for the second uplink data and/or downlink data. Based onreceiving the second response message, the UE may consider thesubsequent transmission (e.g., the sending the second uplink data)successful. Based on the considering, the UE in an RRC idle state or anRRC inactive state may empty uplink buffer for the second uplink data.Based on the completion of the subsequent transmission (e.g., thesending the second uplink data), the UE in an RRC idle state or an RRCinactive state may release the subsequent configuration parameters. Theinformation first response message, e.g., subsequent configurationparameters, may enable a UE to transmit uplink data in inactive/idlewith reduced delay.

In an example embodiment, based on the completion of the subsequenttransmission (e.g., the sending the second uplink data), the UE in anRRC idle state or an RRC inactive state may perform the suspending RRCconnection based on the second suspend configuration parameters. Thesuspending RRC connection based on the second configuration parametersmay comprise that the UE performs at least one of:

-   -   discarding uplink data in uplink buffer;    -   storing the first configuration parameters and the second        security keys;    -   suspending bearers except for SRB0; and/or    -   transitioning to an RRC idle state or an RRC inactive state.

Based on the suspending RRC connection, the UE in an RRC idle state oran RRC inactive state may transition to an RRC idle state or an RRCinactive state. The UE in an RRC idle state or an RRC inactive state mayhave a third uplink data. The UE in an RRC idle state or an RRC inactivestate may perform initiating UP small data transmission (e.g., secondsmall data transmission). the initiating UP small data transmissionusing the second suspend configuration parameters may comprise that theUE perform at least one of:

-   -   restoring the first configuration parameters and the second        security keys;    -   deriving a second resume MAC-I based on the second security        keys;    -   deriving third security keys based on the second security keys        and the second NCC value; and    -   resuming all suspended bearers.

In response to the initiating UP small data transmission using thesecond suspend configuration parameters, the UE may perform sending UPsmall data using the second suspend configuration parameters. Forexample, the sending UP small data using the second suspendconfiguration parameters may comprise that the UE perform at least oneof:

-   -   generating an RRC resume request message by setting the contents        of the RRC resume request message where the RRC resume request        message comprises the second resume identity and the second        resume MAC-I;    -   performing ciphering and/or integrity protection with the third        uplink data based on the third security keys; and/or    -   sending at least one of the RRC resume request message and/or        the third uplink data based on the first configuration        parameters.

In an example, a base station may determine to keep/store the subsequentconfiguration parameters in a UE after the completion of the subsequenttransmission and use the subsequent configuration parameters for nextsmall data transmission. For example, based on determining, the basestation may send a request to keep/store in the UE after the completionof the subsequent transmission and use the subsequent configurationparameters for next small data transmission. The request may indicate tokeep/store one or some or all of the subsequent configurationparameters. For example, the request may indicate to keep/store one orsome parameters of the subsequent configuration parameters. Based onreceiving the request, the UE in an RRC idle state or an RRC inactivestate may store corresponding parameters of the subsequent configurationparameters in response of the completion of the subsequent configurationparameters. For example, the UE in an RRC idle state or an RRC inactivestate may store the corresponding parameters in UE inactive AS context.

In existing technologies, the UE in an RRC idle state or an RRC inactivestate may start an RRC timer to supervise sending an RRC request messagebased on sending the RRC request message (e.g., the second RRC message).In response to receiving an RRC response message in response to the RRCrequest message when the RRC timer is running, the UE may considersending the RRC request message successful and stop the RRC timer (e.g.,T300 or T319). In small data transmission and subsequent transmission,the first response message may not comprise the RRC response message.For example, the last downlink message of subsequent transmission (e.g.,the last response message of subsequent transmission) may comprise theRRC response message. Based on the first response message not comprisingthe RRC response message, the UE may not stop the RRC timer. Based onexpiry of the RRC timer, the UE may consider sending the RRC requestmessage (being) failed. Based on considering the sending the RRC requestmessage (being) failed or expiry of the RRC timer, the UE may perform atleast one of MAC reset, re-establishing RLC entities, suspending RRCconnection or releasing RRC connection. Based on the suspending or thereleasing RRC connection, the UE may release radio resources and/orperform cell (re)selection procedure. Based on the releasing the radioresources and/or the performing cell (re)selection procedure, the UE maynot perform the subsequent transmission. This may delay the transmissionof subsequent packets by the wireless device.

In an example embodiment, a UE may receive, from a first base station, afirst radio resource control (RRC) message comprising a first suspendconfiguration parameters. The UE may send, based on the first suspendconfiguration parameters, a first uplink data and a second RRC messagerequesting to resume an RRC connection. The UE (e.g., an RRC layer ofthe UE) may start, based on the sending the second RRC message, a timer(e.g., an RRC timer) to supervise the sending the second RRC message. Inresponse to the second RRC message, the UE may receive a controlelement. Based on the control element, the UE may stop the timer.

In example, the control element comprises at least one of: medium accesscontrol element (MAC CE); or downlink control information (DCI). The MACCE may be a UE contention resolution identity MAC CE. The UE contentionresolution identity MAC CE may comprise a first 48 bits of commoncontrol channel (CCCH) service data unit (SDU) where the CCCH SDU maycomprises the second RRC message. The DCI may comprise at least one of:downlink assignment; or uplink resource (uplink grant).

In existing technologies, a wireless device may start an RRC timer basedon transmission of an RRC request message. The RRC request message maybe configured to prompt a response from the target of the RRC requestmessage (for example, a base station). If a response to the RRC requestmessage is received, then the RRC timer may be stopped. But if the RRCtimer expires before a response to the RRC message is received, then thewireless device may determine that the response to the RRC requestmessage will not be received. The wireless device may, based on theexpiration, determine that procedures based on RRC signaling (e.g.,resumption of an RRC connection) have failed. The wireless device maystop procedures based on RRC signaling and take other actions.

The wireless device may perform a small data transmission (SDT)procedure while in an RRC non-connected state (e.g., RRC idle or RRCinactive state). The SDT procedure may comprise transmission of SDT datawhile in the RRC non-connected state. The SDT data may be divided into,for example, first data, second data, etc. In the SDT procedure,transmission of the first data may be associated with transmission of anRRC request message. The transmission of the RRC request message maycause a starting of an RRC timer. The RRC timer may expire before thewireless device has an opportunity to transmit subsequent dataassociated with the SDT procedure (e.g., the second data). For example,the wireless device may receive a message from the base station whichfacilitates transmission of subsequent data, but the message may notcomprise an RRC message (and therefore, reception of the message may notstop the RRC timer). As a result, the RRC timer may expire before theSDT procedure is completed.

In embodiments of the present disclosure, a wireless device may transmitfirst data and an RRC message. The wireless device may start an RRCtimer based on the transmitting of the RRC message. The wireless devicemay receive a contention resolution identity medium access control (MAC)control element (CE). The MAC CE is not an RRC message. Accordingly, inexisting implementations, the wireless device may not stop the RRCtimer. In embodiments of the present disclosure, the wireless device maystop the RRC timer based on the receiving of the MAC CE. The stopping ofthe RRC timer may prevent expiration of the RRC timer and discard ofsecond data based on the expiration of the RRC timer. Accordingly,discarding of the second data may be prevented, thereby reducing delayassociated with transmission of the second data.

FIG. 36 illustrates an example of RRC timer for subsequent transmission.A UE may receive, from a first base station, a first RRC message (e.g.,an RRC release message) requesting to release or suspend an RRCconnection. Based on the first RRC message, the UE may transition to anRRC idle state or an RRC inactive state. Based on the first RRC message,the UE in an RRC idle state or an RRC inactive state may perform a cell(re)selection procedure. Based on the cell (re)selection procedure, theUE in an RRC idle state or an RRC inactive state may select a cell 2 ofa second base station (a target base station). The UE in an RRC idlestate or an RRC inactive state may have a first uplink data and a seconduplink data in uplink buffer. The UE in an RRC idle state or an RRCinactive state may determine to perform small data transmission (e.g.,CP small data transmission or UP small data transmission). The UE in anRRC idle state or an RRC inactive state may send (e.g. in Msg 3) atleast one of the first uplink data, a BSR requesting uplink resource forthe second uplink data and a second RRC message for CP small datatransmission or UP small data transmission. For example, for CP smalldata transmission, the second RRC message may be an RRC early datarequest message. Based on the sending of the second RRC message, the UE(e.g., an RRC layer of the UE, UE-RRC layer) may start an RRC timer tosupervise the sending of the second RRC message. When the RRC timer isrunning, the UE waits for another RRC message. For UP small datatransmission, the second RRC message may be an RRC resume requestmessage. When the RRC timer is running, the UE in an RRC idle state oran RRC inactive state may receive a first response message (e.g. Msg 4)in response to at least one of the first uplink, the BSR and/or thesecond RRC message. The first response (e.g. msg4) may comprise acontrol element. In an example, the first response may not an RRCresponse message. For example, the UE in an RRC idle state or an RRCinactive state may receive the RRC response message via a last responsemessage (e.g., a last downlink message) (e.g., in Msg 6) of subsequenttransmission (period). In response to the control element, the UE in anRRC idle state or an RRC inactive state may stop the RRC timer. Forexample, in response to the control element, the UE in an RRC idle stateor an RRC inactive state may determine receiving the (first) responsemessage in response to the second RRC message (being) successful orrandom access procedure successfully completed. Based on thedetermining, the UE in an RRC idle state or an RRC inactive state maystop the RRC timer. For example, in response to the control element, aMAC layer of the UE (e.g., UE-MAC layer) may indicate to the RRC layerof the UE (e.g., the UE RRC layer) the (first) response message inresponse to the second RRC message (being) successful or random accessprocedure successfully completed. Based on the indicating, the RRC layerof the UE may stop the RRC timer. Based on stopping the RRC timer, theUE may consider sending the RRC request message successful. In anexample, based on considering the sending the RRC request message beingsuccessful or stopping of the RRC timer, the UE may not perform at leastone of MAC reset and may not re-establish RLC entities. In an example,the UE may perform the subsequent transmission. An example embodimentmay reduce delay of subsequent transmission of packets.

In an example, the UE in an RRC idle state or an RRC inactive state maydetermine to perform subsequent transmission. In response to the controlelement, the UE in an RRC idle state or an RRC inactive state may stopthe RRC timer based on determining to perform subsequent transmission.For example, the RRC layer of the UE in an RRC idle state or an RRCinactive state may indicate to the MAC layer of the UE in an RRC idlestate or an RRC inactive state the determining to perform subsequenttransmission or the RRC layer of the UE in an RRC idle state or an RRCinactive state may configure the subsequent transmission to the MAClayer of the UE. For example, the configuring may comprise configuringMAC configuration parameters for subsequent transmission to the MAClayer of the UE. In response to the control element, the MAC layer ofthe UE in an RRC idle state or an RRC inactive state may indicate to theRRC layer of the UE (e.g., the UE RRC layer) the (first) responsemessage in response to the second RRC message (being) successful orrandom access procedure successfully completed based on determining toperform subsequent transmission or configuring the subsequenttransmission. Based on the indicating, the RRC layer of the UE may stopthe RRC timer.

In example, the UE may perform EDT RACH. Based on the EDT RACH, thecontrol element may comprise a UE contention resolution identity MAC CE.the UE (e.g., the MAC layer of the UE, the UE-MAC layer) may ignore thecontents of the UE contention resolution identity MAC CE (field). Forexample, in response to the UE contention resolution identity MAC CE,the MAC layer of the UE may ignore the contents of the UE contentionresolution identity MAC CE (field) based on determining to performsubsequent transmission or configuring the subsequent transmission.

In an example, the UE in an RRC idle state or an RRC inactive state maynot perform random access procedure for sending uplink signaling/datausing PUR. Based on the sending uplink signaling/data using PUR, thecontrol element may comprise at least one of downlink message (e.g.,DCI) and/or a MAC CE. For example, the downlink message may comprise atleast one of:

-   -   the downlink message indicating an uplink grant for        retransmission;    -   the downlink message indicating L1 (layer 1) ack for PUR;    -   the downlink message indicating fallback for PUR; and/or    -   the downlink message indicating PDCCH transmission (downlink        grant or downlink assignment) addressed to the PUR RNTI and/or        MAC PDU comprising the uplink data being successfully decoded;    -   a downlink message indicating subsequent transmission allowance.

In an example, the UE in an RRC idle state or an RRC inactive state mayreceive the MAC CE via the PDCCH transmission of a base station. Forexample, the control element may be the downlink message indicatingfallback for PUR or the downlink message indicating PDCCH transmission(downlink grant or downlink assignment) addressed to the PUR RNTI and/orMAC PDU comprising the uplink data being successfully decoded. Forexample, based on receiving the downlink message indicating fallback forPUR, the UE in an RRC idle state or an RRC inactive state may determinethe (first) response message in response to the second RRC message(being) failed or random access procedure successfully not completed.Based on the determining, the UE may stop the RRC timer. For example,based on the determining, the UE may start a wait timer. The UE in anRRC idle state or an RRC inactive state may not perform a random accessprocedure or uplink transmission using PUR until the wait timer beingexpired.

A UE may receive, from a first base station, a first radio resourcecontrol (RRC) message comprising first suspend configuration parameters.The UE may send, based on the first suspend configuration parameters,first uplink data and a second RRC message requesting to resume an RRCconnection. The UE may receive, in response to the second RRC message, athird RRC message comprising second suspend configuration parameters.The UE may send, after the receiving the third message, second uplinkdata using the first suspend configuration parameters. The UE may send,based on completion of the sending the second uplink data, third uplinkdata using the second suspend configuration parameters.

The receiving the first RRC message may comprise receiving the first RRCmessage further based on first configuration parameters of the wirelessdevice for the first base station and first security keys of thewireless device for the first base station.

Based on the first suspend configuration parameters, the RRC connectionwherein the first suspend configuration parameters may comprise a firstnext hop chaining count (NCC) value or a first resume identity.

The suspending based on the first suspend configuration parameters theRRC connection may comprise suspending based on the first suspendconfiguration parameters the RRC connection in response to at least oneof sending successfully acknowledgment for the first RRC message orafter configured time from the moment of the receiving the first RRCmessage.

The suspending based on the first suspend configuration parameters theRRC connection may comprise at least one of discarding all uplink datain uplink buffer, storing the first configuration parameters and thefirst security keys, suspending all bearers except signaling radiobearer 0 (SRB0) or transitioning to either an RRC idle state or an RRCinactive state.

The UE may initiate, based on small data transmission condition beingmet, small data transmission using the first suspend configurationparameters before the sending the first uplink data and the second RRCmessage wherein the initiating for small data transmission using thefirst suspend configuration parameters comprises at least one ofderiving, based on the first security keys, a first resumeauthentication code-integrity (MAC-I), deriving, based on the first NCCvalue and the first security keys, second security keys or resuming thesuspended bearers.

The UE may send, based on the sending the first uplink and the secondRRC message, buffer status report (BSR) requesting uplink resource forthe second uplink data wherein the BSR is multiplexed with the firstuplink data and the second RRC message.

The sending the first uplink data and a second RRC message may comprisesending the first uplink data and a second RRC message based on uplinkresource for a first cell of a second base station.

The uplink resource for the first cell may comprise at least one ofdynamic uplink resource wherein the dynamic uplink resource is receivedvia the first cell in response of random access preamble of the wirelessdevice or preconfigured uplink resource (PUR) for the first cell in PURconfiguration parameters of the wireless device.

The sending the first uplink data and the second RRC message maycomprise sending the first uplink data and the second RRC message basedon the first configuration parameters and the second security keys.

The second RRC message may comprise at least one of the first resumeidentity or the first resume MAC-I.

The receiving the third RRC message may comprises receiving the thirdRRC message based on the first configuration parameters and the secondsecurity keys.

The sending the second uplink data may comprise sending the seconduplink data based on the first configuration parameters and the secondsecurity keys.

The UE may receive, from the first base station or the second basestation, subsequent transmission allowance information.

The UE may delay, based on the subsequent transmission allowanceinformation, suspending the RRC connection based on the second suspendconfiguration parameters in response to the receiving the third RRCmessage.

The third RRC message comprises at least one of subsequent transmissionallowance information or downlink data.

The third RRC message further may comprise subsequent configurationparameters wherein the subsequent configuration parameters comprise atleast one of physical layer configuration parameters for subsequenttransmission on the first cell and/or MAC layer configuration parametersfor subsequent transmission on the first cell.

The sending the second uplink data may comprise sending the seconduplink data further based on the subsequent configuration parameters.

The UE may release, based on the completion of the sending the seconduplink data, the subsequent configuration parameters.

The suspending based on the second suspend configuration parameters theRRC connection may comprise suspending based on the second suspendconfiguration parameters the RRC connection in response to thecompletion of the sending the second uplink data wherein the secondsuspend configuration parameters comprise a second next hop chainingcount (NCC) value or a second resume identity.

The UE may determine the completion of the sending the second uplinkdata based on at least one of receiving, via the first cell,acknowledgement for the second uplink data, receiving, via the firstcell, fallback indication or reception of a response of the seconduplink data, via the first cell, being failed.

The suspending based on the second suspend configuration parameters theRRC connection may comprise at least one of discarding all uplink datain uplink buffer, storing the first configuration parameters and thesecond security keys, suspending all bearers except signaling radiobearer 0 (SRB0) or transitioning to either an RRC idle state or an RRCinactive state.

The UE may initiate, based on the small data transmission conditionbeing met, small data transmission using the second suspendconfiguration parameters before sending the third uplink data whereinthe initiating small data transmission using the second suspendconfiguration parameters comprises at least one of deriving, based onthe second security keys, a second resume MAC-I, deriving, based on thesecond NCC value and the second security keys, third security keys orresuming the suspended bearers.

The UE may send, based on the initiating small data transmission usingthe second suspend configuration parameters, a fourth RRC messagemultiplexed with the third uplink data before sending the third uplinkdata wherein the fourth RRC message comprises at least one of the secondresume identity or the second resume MAC-I.

The sending the third uplink data and the fourth RRC message maycomprise sending the third uplink data and the fourth RRC messagefurther based on the first configuration parameters and the thirdsecurity keys.

The first configuration parameters may comprise at least one of robustheader compression (ROHC) state or quality of service (QoS) flow to dataradio bearer (DRB) mapping rules.

The PUR configuration parameters comprises at least one of the PUR forone or more cells wherein the PUR is one or more transmission blocksallowed to use in RRC idle state or RRC inactive state, time alignment(TA) validation condition for the one or more cell wherein the timealignment validation condition comprises one or more received signalstrength (RSRP) threshold associated to time alignment value of the oneor more cell.

The uplink resource, based on time alignment validation condition forthe first cell being met, may comprise the PUR for the first cell.

The UE may select, based on a signal quality of the cell exceeding athreshold, the first cell of the second base station in response to thesuspending based on the first suspend configuration parameters the RRCconnection.

The sending the first uplink data and the second RRC message maycomprise sending the first uplink data and the second RRC message viathe first cell.

The first base station may be the second base station.

The UE may select, based on a signal quality of the cell exceeding athreshold, a second cell of a third base station in response to thesuspending the RRC connection based on the second suspend configurationparameters.

The sending the third uplink data may comprise sending the third uplinkdata via the second cell.

The second base station may be the third base station.

The small data transmission condition may comprises at least one of anindication for support of the small data transmission being broadcastedby a cell or the wireless device supporting the small data transmission.

A first base station may receive, from a wireless device, a first radioresource control (RRC) message comprising first suspend configurationparameters. A second base station may receive, based on the firstsuspend configuration parameters, first uplink data and a second RRCmessage requesting to resume an RRC connection. The second base stationmay send, in response to the second RRC message, a third RRC messagecomprising second suspend configuration parameters. The second basestation may receive, after the receiving the third RRC message, seconduplink data using the first suspend configuration parameters. A thirdbase station may receive, based on completion of the sending the seconduplink data, third uplink data using the second suspend configurationparameters.

The sending the first RRC message may comprise sending the first RRCmessage based on first configuration parameters of the wireless devicefor the first base station and first security keys of the wirelessdevice for the first base station.

The receiving the first uplink data and the second RRC message maycomprise receiving the first uplink data and the second RRC message viaa first cell of a second base station.

The second base station may receive, based on the receiving the firstuplink and the second RRC message, buffer status report (BSR) requestinguplink resource for the second uplink data wherein the BSR ismultiplexed with the first uplink data and the second RRC message.

The receiving the first uplink data and the second RRC message maycomprise receiving the first uplink data and the second RRC messagebased on the first configuration parameters and the second securitykeys.

The sending the third RRC message may comprise sending the third RRCmessage based on the first configuration parameters and the secondsecurity keys.

The receiving the second uplink data may comprise receiving the seconduplink data based on the first configuration parameters and the secondsecurity keys.

The first base station or the second base station may send subsequenttransmission allowance information.

The receiving the second uplink data may comprise receiving the seconduplink data further based on the subsequent configuration parameters inresponse to the sending the third RRC message comprising the subsequentconfiguration parameters.

The second base station may release, based on the completion of thereceiving the second uplink data, the subsequent configurationparameters.

The second base station may determine the completion of the receivingthe second uplink data based on at least one of sending acknowledgementfor the second uplink data or sending fallback indication.

The receiving the third uplink data comprises receiving the third uplinkdata via a second cell of a third base station.

The third base station may receive, via the second cell, a fourth RRCmessage multiplexed with the third uplink data.

The receiving the third uplink data and the fourth RRC message maycomprise receiving the third uplink data and the fourth RRC messagefurther based on the first configuration parameters and the thirdsecurity keys.

A UE may receive, from a first base station, a first radio resourcecontrol (RRC) message comprising first suspend configuration parameters.The UE may send, based on the first suspend configuration parameters,first uplink data and a second RRC message requesting to resume an RRCconnection. The UE may receive, in response to the second RRC message, athird RRC message requesting to release the RRC connection. The UE maysend, after the receiving the third RRC message, second uplink datausing the first suspend configuration parameters. The UE may release,based on the third message, the RRC connection in response to completionof the sending the second uplink data.

The UE may delay, based on the subsequent transmission allowanceinformation, the releasing the RRC connection in response to thereceiving the third RRC message.

The releasing the RRC connection may comprise at least one of discardingall uplink data in uplink buffer, releasing all radio resources for allbearers, releasing the first suspend configuration parameters,discarding the second security keys or transitioning to an RRC idlestate.

A UE may receive, from a first base station, a first radio resourcecontrol (RRC) message comprising a first suspend configurationparameters. The UE may send, based on the first suspend configurationparameters, a first uplink data and a second RRC message requesting toresume an RRC connection. The UE may start, based on the sending thesecond RRC message, an RRC timer to supervise the sending the second RRCmessage. The UE may receive, in response to the second RRC message, acontrol element. The UE may stop, based on the control element, the RRCtimer.

The control element may comprise at least one of medium access controlcontrol element (MAC CE) or downlink control information (DCI).

The MAC CE may comprise a UE contention resolution identity MAC CE.

The UE contention resolution MAC CE may comprise a first 48 bits ofcommon control channel (CCCH) service data unit (SDU).

The CCCH SDU may comprise the second RRC message.

The DCI may comprise at least one of downlink assignment or uplinkresource (uplink grant).

The receiving the control element may comprise receiving the controlelement via a first cell.

The invention claimed is:
 1. A method comprising: receiving, by awireless device from a base station, a first radio resource control(RRC) release message comprising a suspend configuration associated witha first bandwidth part (BWP); and while the wireless device is in an RRCidle state or an RRC inactive state: transmitting, by the wirelessdevice, based on the suspend configuration: first data associated with asmall data transmission (SDT) procedure; and an RRC message requestingto resume an RRC connection; receiving, by the wireless device, a secondRRC release message comprising a subsequent configuration associatedwith a second BWP; and transmitting via the second BWP, by the wirelessdevice based on the subsequent configuration, second data associatedwith the SDT procedure.
 2. The method of claim 1, further comprisingtransitioning, by the wireless device, based on the first RRC releasemessage, to the RRC idle state or the RRC inactive state.
 3. The methodof claim 1, wherein the first data associated with the SDT procedureand/or the RRC message requesting to resume the RRC connection areincluded in a message comprising a buffer status report (BSR) for thesecond data associated with the SDT procedure.
 4. The method of claim 1,wherein the first data associated with the SDT procedure and/or the RRCmessage requesting to resume the RRC connection are included in a Msg3.5. The method of claim 1, wherein the second RRC release message isincluded in a Msg4.
 6. The method of claim 1, wherein the second data isincluded in a Msg5.
 7. The method of claim 1, wherein the second RRCrelease message indicates terminating of the SDT procedure.
 8. Themethod of claim 1, further comprising terminating the SDT based on thesecond RRC release message.
 9. The method of claim 1, wherein thetransmitting of the first data is via one or more data radio bearers(DRBs).
 10. The method of claim 1, wherein the transmitting of the firstdata is based on one or more of: integrity protection of the first data;and ciphering of the first data.
 11. A wireless device comprising one ormore processors and memory storing instructions that, when executed bythe one or more processors, cause the wireless device to: receive, froma base station, a first radio resource control (RRC) release messagecomprising a suspend configuration associated with a first bandwidthpart (BWP); while in an RRC idle state or an RRC inactive state:transmit, based on the suspend configuration: first data associated witha small data transmission (SDT) procedure; and an RRC message requestingto resume an RRC connection; receive a second RRC release messagecomprising a subsequent configuration associated with a second BWP; andtransmit via the second BWP, based on the subsequent configuration,second data associated with the SDT procedure.
 12. The wireless deviceof claim 11, wherein the instructions further cause the wireless deviceto transition, based on the first RRC release message, to the RRC idlestate or the RRC inactive state.
 13. The wireless device of claim 11,wherein the first data associated with the SDT procedure and/or the RRCmessage requesting to resume the RRC connection are included in amessage comprising a buffer status report (BSR) for the second dataassociated with the SDT procedure.
 14. The wireless device of claim 11,wherein the first data associated with the SDT procedure and/or the RRCmessage requesting to resume the RRC connection are included in a Msg3.15. The wireless device of claim 11, wherein the second RRC releasemessage is included in a Msg4.
 16. The wireless device of claim 11,wherein the second data is included in a Msg5.
 17. The wireless deviceof claim 11, wherein the second RRC release message indicatesterminating of the SDT procedure.
 18. The wireless device of claim 11,wherein the instructions further cause the wireless device to terminatethe SDT based on the second RRC release message.
 19. The wireless deviceof claim 11, wherein the transmitting of the first data is via one ormore data radio bearers (DRBs).
 20. A system, comprising: a wirelessdevice comprising: one or more processors and memory storinginstructions that, when executed by the one or more processors, causethe wireless device to: receive, from a base station, a first radioresource control (RRC) release message comprising a suspendconfiguration associated with a first bandwidth part (BWP); while in anRRC idle state or an RRC inactive state: transmit, based on the suspendconfiguration: first data associated with a small data transmission(SDT) procedure; and an RRC message requesting to resume an RRCconnection; receive a second RRC release message comprising a subsequentconfiguration associated with a second BWP; and transmit via the secondBWP, based on the subsequent configuration, second data associated withthe SDT procedure a base station comprising: one or more processors andmemory storing instructions that, when executed by the one or moreprocessors, cause the base station to: transmit the first RRC releasemessage; receive the first data and the RRC message requesting to resumethe RRC connection; transmit the second RRC release message; and receivethe second data.